EI 1550 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 About the Energy Institute With a combined membership of over 13,000 individuals and 300 companies across 100 countries, the Energy Institute (EI) is the leading chartered professional membership body for those working in energy. Providing an independent focal point and a powerful voice to engage business and industry, government, academia and the public, the EI promotes the safe, environmentally responsible and efficient supply and use of energy in all its forms and applications. In fulfilling this purpose the EI addresses the depth and breadth of energy and the energy system, from upstream and downstream hydrocarbons and other primary fuels and renewables, to power generation, transmission and distribution to sustainable development, demand side management and energy efficiency. Offering learning and networking opportunities to support career development, the EI provides a home to all those working in energy, and a scientific and technical reservoir of knowledge for industry. This publication has been produced as a result of the work carried out within the Technical Team of the EI, funded by the EI’s Technical Partners. The EI’s technical work programme provides industry with cost-effective, value-adding knowledge on key current and future issues affecting those operating in the energy sector, both in the UK and Internationally. To find out more about the work of the Energy Institute, visit www.energyinst.org.uk 61 New Cavendish Street, London W1G 7AR, UK t: +44 (0)20 7467 7100 For further information about EI aviation titles, see inside back cover Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 EI 1550 HANDBOOK ON EQUIPMENT USED FOR THE MAINTENANCE AND DELIVERY OF CLEAN AVIATION FUEL October 2007 Published by ENERGY INSTITUTE, LONDON The Energy Institute is a professional membership body incorporated by Royal Charter 2003 Registered charity number 1097899 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Legal notices and disclaimers The information contained in this publication is provided as guidance only, and although every effort has been made by the Energy Institute (EI) to assure the accuracy and reliability of its contents, neither THE EI nor any of THE EI’s employees, subcontractors, consultants or others assigns GUARANTEE THAT THE INFORMATION HEREIN IS COMPLETE OR ERROR-FREE. ANY PERSON OR ENTITY MAKING ANY USE OF THE INFORMATION HEREIN DOES SO AT HIS/HER/ITS OWN RISK. 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The EI is not undertaking to meet the duties of manufacturers, purchasers, users and/or employers to warn and equip their employees and others concerning safety risks and precautions, nor is the EI undertaking any of the duties of manufacturers, purchasers, users and/or employers under local and regional laws and regulations. This information should not be used without first securing competent advice with respect to its suitability for any general or specific application, and all entities have an independent obligation to ascertain that their actions and practices are appropriate and suitable for each particular situation and to consult all applicable federal, state and local laws. THE EI HEREBY EXPRESSLY DISCLAIMS ANY LIABILITY OR RESPONSIBILITY FOR LOSS OR DAMAGE RESULTING FROM THE VIOLATION OF ANY LOCAL OR REGIONAL LAWS OR REGULATIONS WITH WHICH THIS PUBLICATION MAY CONFLICT. 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The Energy Institute gratefully acknowledges the financial contributions towards the scientific and technical programme from the following companies: BG Group BHP Billiton Limited BP Exploration Operating Co Ltd BP Oil UK Ltd Chevron ConocoPhillips Ltd ENI ExxonMobil International Ltd Kuwait Petroleum International Ltd Maersk Oil North Sea UK Limited Murco Petroleum Ltd Nexen Saudi Aramco Shell UK Oil Products Limited Shell U.K. Exploration and Production Ltd Statoil (U.K.) Limited Talisman Energy (UK) Ltd Total E&P UK plc Total UK Limited Copyright © 2010 by The Energy Institute, London: The Energy Institute is a professional membership body incorporated by Royal Charter 2003. Registered charity number 1097899, England All rights reserved No part of this book may be reproduced by any means, or transmitted or translated into a machine language without the written permission of the publisher. ISBN 978 0 85293 574 3 Published by the Energy Institute, London. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 2 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Contents Foreword .......................................................................................................................................................... 4 Acknowledgements.................................................................................................................................................... 5 Chapters Chapter 1 Introduction...................................................................................................................................... 6 Chapter 2Aviation fuel handling systems........................................................................................................... 8 Chapter 3Fuel cleanliness................................................................................................................................. 12 Chapter 4Description of components............................................................................................................... 20 Chapter 5 Relating EI specifications to end use of filters.................................................................................... 28 Chapter 6 Laboratory testing requirements....................................................................................................... 32 Chapter 7Filter/water separators (EI 1581)........................................................................................................ 42 Chapter 8Similarity for filter/water separators (EI 1582).................................................................................... 46 Chapter 9Filter monitors (EI 1583).................................................................................................................... 48 Chapter 10Microfilters (EI 1590)........................................................................................................................ 52 Chapter 11Dirt defence filters (EI 1599)............................................................................................................. 54 Chapter 12 Three-stage filtration (vessels)........................................................................................................... 56 Chapter 13Filter vessels (EI 1596)....................................................................................................................... 58 Chapter 14 Electronic sensors (EI 1598)............................................................................................................... 62 Chapter 15 Quality assurance of filter element and vessel manufacture............................................................... 64 Chapter 16Application of components in aviation fuel handling systems............................................................ 66 Chapter 17 Operation of filter vessels - general health and safety considerations................................................ 74 Chapter 18 Recommendations for operation of filter vessels............................................................................... 76 Chapter 19Service life of filter elements............................................................................................................. 80 Chapter 20Disposal of used filter elements........................................................................................................ 82 Annexes Annex ADefinition of ‘the industry’................................................................................................................ 84 Annex BAircraft engine fuel filters and engine tolerance of particulate matter and free water........................ 86 Annex C IATA guidance material for fuel contamination limits........................................................................ 88 Annex D Traditional methods for the assessment of fuel cleanliness................................................................ 90 Annex EFiltration ratings, absolute, nominal and Beta ratios.......................................................................... 94 Annex F Clay treatment................................................................................................................................. 96 Annex GFilter/coalescer disarming.................................................................................................................. 98 Annex HSuper-absorbent polymer (SAP)....................................................................................................... 100 Annex I Conversion of filter/water separator vessels for use with microfilter elements.................................. 102 Annex J Conversion of filter/water separator or microfilter vessels for use with filter monitor elements........ 104 Annex K Low point sampling/draining.......................................................................................................... 108 Annex L Electrical resistance measurement procedure for filter vessels.......................................................... 110 Annex M Concept of aviation fuel regulation................................................................................................. 114 Annex NDefinitions...................................................................................................................................... 116 Annex OBibliography................................................................................................................................... 118 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 3 Foreword This publication was prepared on behalf of the EI Aviation Committee by Phil Rugen (Shell Global Solutions), Vic Hughes (Vic Hughes Associates Ltd) and Martin Hunnybun (EI), with other contributions by Dennis Hoskin (ExxonMobil Research & Engineering) and Nic Mason (Air BP). This publication describes how to maintain aviation fuel cleanliness from the point of fuel certification to into-plane delivery. It has been prepared in order to communicate key information on the application and use of aviation fuel filtration components and electronic sensors for the detection of free water and/or particulate matter in aviation fuel handling systems. This includes operational experiences from users, findings from industry research, explanations of laboratory qualification test requirements included in EI filter specifications and details of potential application of technologies not previously used in such systems. This publication is intended for a wide range of industry practitioners including those that design aviation fuel handling systems, specify and/or purchase equipment/components for use in such systems, manufacturers and users of equipment/components, operators of pipelines, operators of pre-airport terminals and depots and those that operate aviation fuel supply facilities at airports. This publication should not be considered as a replacement for the recommendations of aviation fuel filter manufacturers, or the manufacturers of electronic sensors, which should be followed at all times. Neither does it absolve the responsibility of manufacturers of such components to clearly communicate to users of their products, their correct operation and any application/operational limitations that may exist. At the time of publication industry representatives were engaged in the preparation of SAE Aerospace Standard AS 6401 provisionally titled Storage, handling and distribution of aviation fuels at airfields. It is the intention that that publication will become the international reference for operators worldwide. EI 1550 will be revised in future to take into account the requirements of AS 6401. This publication also addresses key aspects of operational requirements for equipment and filtration systems. It is assumed that all users of this publication are either fully trained or under the supervision of a responsible trained person who is familiar with all normal engineering safety practice, and that all such precautions are observed. Users of this publication are responsible for ensuring compliance with the requirements of locally prevailing health and safety regulations. This publication uses the Systemé International d’Unités (International System of Units, or SI), with the exception of pressure which is given in psi. In this system, the decimal point is a comma (,). In writing numbers of greater than 3 digits, thousands are demarcated by the use of a space, rather than a comma. US Customary Units are also given in parentheses after the SI unit. Suggested revisions are invited and should be submitted to the Technical Department, Energy Institute, 61 New Cavendish Street, London, W1G 7AR (e: [email protected]). They can also be submitted via www.energyinst.org.uk/filtration. Information regarding amendments/updates to this publication will also be posted at that site, to which readers are referred. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 4 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Acknowledgements The principal contributors to the drafting of EI 1550 have been Phil Rugen (Shell Global Solutions), Vic Hughes (Vic Hughes Associates Ltd) and Martin Hunnybun (EI). Text has also been contributed by Dennis Hoskin (ExxonMobil Research & Engineering) and Nic Mason (Air BP). Co-ordination and editing was undertaken by Martin Hunnybun. The text has also been extensively reviewed by the following members of the EI Aviation Fuel Filtration Committee. All are thanked sincerely for their assistance. John BuxtonShell Aviation Ltd. Michel CamposAir TOTAL International Dennis Hoskin ExxonMobil Research & Engineering Martin Hunnybun EI Nic MasonAir BP Limited Ken McCarley ConocoPhillips Limited Phil RugenShell Global Solutions Ed Selley Kuwait Petroleum International Aviation Company Ltd. David SoffrinAPI Ralf WestphalAFS Aviation Fuel Services GmbH Phil Wetmore Chevron Ltd A draft version was distributed to over 100 industry stakeholders for technical review. The following generously gave of their time to provide feedback, which is greatly appreciated: Steve Anderson (Air BP), Mark Bourdeau (United Air Lines), Jim Gammon (Gammon Technical Products), John Hereford (ConocoPhillips), Dennis Hughes (Liquip), IATA Fuel Quality Pool members, Chris Jones (ExxonMobil Aviation), Michael Jones (Boeing), Gilles Kergutuil (Air TOTAL International), Robin Mason (Velcon Filters), Ron McDowell (Facet USA), John Rhode (Air BP), Tony Rowe (Joint Inspection Group), Stan Seto (Belcan/GE), Steven Shaeffer (US Air Force Petroleum Office), Greg Sprenger (Velcon Filters), Kurt Strauss (Consultant), Marcus Wildschütz (Faudi Aviation) and George Zombanakis (Continental Airlines). The following companies/individuals assisted by the provision of images for use in this publication. In each case the copyright remains with the originator: Michel Campos (Air TOTAL International), Jim Gammon (Gammon Technical Products), Dennis Hughes (Liquip), Vic Hughes (Vic Hughes Associates Ltd), Martin Hunnybun (EI), Charlie Laudage (Allied New York Services, Inc.), Nic Mason (Air BP), Ken McCarley (ConocoPhillips Limited), Ron McDowell (Facet USA), John Rhode (Air BP), Phil Rugen (Shell Global Solutions), Greg Sprenger/Robin Mason (Velcon Filters), Paul Wells (ExxonMobil Research & Engineering) and Marcus Wildschütz (Faudi Aviation). Layout and formatting was undertaken by Joanna Stephen and Erica Sciolti (both EI). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 5 Chapter 1 Introduction This chapter explains who this publication is intended for, what 1550 does and does not cover, and why the EI has produced it. Who is 1550 for? This publication provides information for: Equipment/component users at airports are typically major international oil companies, national oil companies, independent into-plane agents, airlines, or in some cases, airports. • Designers of aviation fuel handling systems (including aviation filter systems and other fuel cleanliness monitoring/control equipment). • Those responsible for specifying and purchasing equipment/components for use in aviation fuel handling systems. • Manufacturers of equipment/components (including vehicles) typically used in aviation fuel handling systems. • Pipeline operators. • Pre-airport/pre-airfield depot/terminal operators. • Operators of aviation fuel supply facilities at airports/airfields. • Equipment/component operators/users. • Those responsible for purchasing aviation fuel. • Other standards developing organisations that may wish to reference EI equipment/ component specifications. What does 1550 cover? For definitions of batch and into-plane see chapter 2. commercial In this sense refers to the supply of aviation fuel to a company that typically operates a fleet of aircraft for the transport of paying passengers or freight, such as major international airlines. Civilian (civil) refers to any operation that is nonmilitary. This publication provides information on: • Maintaining aviation fuel cleanliness from batch release/point of fuel certification to intoplane delivery for civilian (mainly commercial) applications. • The design, installation and operation of filtration/water removal equipment used in aviation fuel handling systems to ensure fuel cleanliness. • Operational characteristics of different system components as applied in the aviation fuel handling system. This includes discussion of known limitations in the use of particular types of components. • Certain aspects of the design of other fuel cleanliness monitoring/control equipment that may be used in aviation fuel handling systems in the near future. • Key issues to be considered in the selection and use of combinations of various technologies/quality assurance procedures to achieve the required fuel cleanliness. • Other standards or publications that should be consulted for additional in depth information. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file1is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 6 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Introduction Why the need for 1550? This publication has been prepared to: EI specifications for filters are primarily written for use by filter manufacturers in filter design and laboratory qualification of a model design. This publication is primarily intended for equipment/component users. • Communicate key information on the above topics to assist all those listed above. • Provide information based on operational experiences that may benefit the industry and provide specific references to other publications where appropriate. • Disseminate key findings from relevant industry research to users of equipment/ components who may not be directly involved in all research activities. • Provide information that may assist in the optimisation of aviation fuel handling system components in terms of safety and efficiency. • Provide information on technologies not previously used in aviation fuel handling systems that may be introduced in the near future. • Highlight the benefits of using combinations of components. What 1550 does not cover Note 1: Further advice should be sought from manufacturers and suppliers of fuel handling equipment for specific military applications. • 1550 does not specifically address military applications. However, much of the information may be applicable1. • 1550 has been written by technical experts involved primarily in the supply of jet fuel to commercial aircraft. The information may therefore have limited application to maintaining cleanliness of aviation gasoline fuels (which may form a large part of the ‘general aviation’ market), or to very small airfield installations. It is hoped that a future edition of 1550 will cover some of the more specific requirements for aviation gasoline cleanliness. (Note some aviation gasoline points are included in chapter 3 and chapter 16.) • 1550 should not be considered an operations manual. All operators of aviation fuel handling systems and equipment/components should have their own detailed operating procedures. • 1550 does not include detailed information or operational recommendations from equipment/component manufacturers. Such information should always be provided by manufacturers, and followed by users. • 1550 does not provide general fuel handling design and operational recommendations that do not specifically relate to fuel cleanliness, see ‘Where can I find further information?’ below. Where can I find further information? If what you are looking for is not outlined above, you might not find it in 1550. Other sources of related information are included in Annex O (see also inside back cover). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 1 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 7 Chapter 2 Aviation fuel handling systems Fuel cleanliness is a property that must be managed throughout the process of moving jet fuel from production to use Fuel quality batch After production at a refinery, aviation fuel is required to be analysed and certified. This process has to be undertaken on the quantity of fuel contained in a single storage tank, rather than continuously, so once analysed and certified as aviation fuel, that material is described as a batch. With over 20 specified performance parameters, jet fuel remains one of the most highly specified fuels (products) produced by refineries. All but one of these parameters have quantifiable limits that are measured by a range of well-defined, industry-recognised analytical methods. The parameters measured relate to fuel performance or compositional features determined by crude oil type and refinery processing, see box below. The single exception is fuel cleanliness. Whilst the other parameters remain relatively unchanged from the batch process at the refinery until it is delivered into-plane (cross-contamination between different products is unusual), it is inevitable that cleanliness is affected by the entrainment of particulate matter, microbes and dispersed water. Such contamination can be introduced into fuel at any stage in the distribution system. For further details of fuel cleanliness see chapter 3. into-plane Is a term used by fuel handling companies to describe the point of delivery of fuel to an aircraft. Also sometimes referred to as into-wing. Key measurable parameters for aviation fuel Appearance Fluidity Stability Lubricity Additives Composition Combustion Contaminants Volatility Corrosion Conductivity Philosophy for maintaining fuel cleanliness The typical contaminants found in fuels can have undesirable effects on many of the operations carried out both on the ground and in aircraft. Over many years of experience the industry has developed robust measures to deal with, and manage this. The philosophy adopted may be summarised as follows: For the definition of the industry see Annex A. For the definition of contaminants see chapter 3. • The presence of contaminants in jet fuel is undesirable. • Prevention is safer, and more cost effective, than remediation. • Aviation fuel handling systems should be designed and constructed so as to not adversely affect fuel cleanliness and to facilitate the maintenance of fuel cleanliness. • Jet fuel is usually filtered at each transfer to remove dispersed contaminants down to acceptable levels. • System monitoring is encouraged. Monitoring, and the application of preventative measures, should be part of any aviation fuel handling system and procedures. Specific details greatly depend on the particular location (fuel throughput) and stage in the distribution system. Methods for the removal of contaminants are so critical to the industry that they are the subject of specific industry publications. Several laboratory test specifications for filtration components are published by EI and are shown in Figure 1, which also highlights the relationship between those publications and this one. It is recommended that, where an EI specification exists for a specific component, only components meeting, or exceeding, the requirements of the relevant specification should be used in the aviation fuel handling system. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file2is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 8 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Aviation fuel handling systems Note 2: This wording is included in jet fuel specifications, see page 11. Into-plane requirements for fuel cleanliness can be achieved with certainty only by the combined use of stringent quality assurance procedures and filtration and water removal equipment deployed throughout the aviation fuel handling system. Aviation fuel needs to be kept clean, dry and free from particulate matter.2 EI 1550 Handbook on equipment used for the maintenance and delivery of clean aviation fuel EI Specification 1581 EI Standard 1541 EI Standard 1541 Specifications and qualification procedures for aviation jet fuel filters/ separators Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping 5th edition, 2002 EI Draft standard 1583 EI Standard 1541 EI Standard 1541 Laboratory tests and minimum performance standards for aviation fuel filter monitors Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping 5th edition, 2006 EI Specification 1590 EI Standard 1541 EI Standard 1541 Specifications and qualification procedures for aviation fuel microfilters Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping 2nd edition, 2002 EI Specification 1596 EI Standard 1541 EI Standard 1541 Design and construction of aviation fuel filter vessels Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping 1st edition, 2006 EI Draft std 1598 EI Specification 1599 EI Standard 1541 EI Standard 1541 EI Standard 1541 EI Standard 1541 Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping Considerations for electronic sensors to monitor free water and/or particulate matter in aviation fuel 1st edition, 2007 Laboratory tests and minimum performance levels for aviation fuel dirt defence filters 1st edition, 2007 EI Specification 1581 EI Standard 1541 EI Standard 1541 Specifications and qualification procedures for aviation jet fuel filters/separators Performance requirements for Performance requirements for in protective coating systems used protective usedpiping in aviation fuelcoating storagesystems tanks and aviation fuel storage tanks and piping 5th edition, 2002 Figure 1: EI aviation fuel cleanliness publications Aviation fuel needs to be kept clean, dry and free from particulate matter To maintain the highest level of fuel quality, the industry has developed an operational strategy that uses combinations of available technologies rather than depending on just one. Such a strategy recognises that reliance should not be placed in one type of technology, even if it is claimed, or considered to be, ‘fail-safe’. One aspect of this publication is to provide information to help decision makers evaluate which combination options are available, and which might yield optimal commercial and technical performance. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 2 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 9 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Aviation fuel handling system description A schematic diagram to provide an illustration (generic) of the aviation fuel handling system (typical jet fuel manufacture, distribution and supply) is shown in Figure 2. It also shows locations where fuel filtration (F) may be applied, (into pre-airfield/terminal storage, out of pre-airfield/terminal storage, into airport storage, out of airport storage and into-plane through refuellers, hydrant services/carts or kerbside pumping equipment). Note that local regulations and practice may cause actual systems to be slightly different. However the essential steps are the same. Manufacture Refinery Distribution Road Rail Pipeline Barge (river) Ship (marine) Terminal F F Supply F Hydrant F F F Figure 2: Generic aviation fuel handling system Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file2is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 10 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Aviation fuel handling systems Jet A is the most commonly used jet fuel in the USA. The main difference from Jet A-1 is the freeze point of the fuel. (UK) Ministry of Defence Defence Standard 91-91 Turbine fuel, Aviation kerosine type, Jet A-1, NATO Code F-35, Joint service designation: AVTUR (free to download from www.dstan.mod.uk) ASTM D 1655 Standard specification for aviation turbine fuels Note 3: The method used will vary between locations. It may involve a check of paperwork, a short list of typically five tests (e.g. if fuel has arrived from a dedicated system), or full certification. Manufacture Most aviation fuel originates from refinery processing of crude oil. It is made to a local specification or, more commonly, one of the major international specifications (e.g. for jet fuel, Defence Standard 91-91 (for jet A-1) or ASTM D 1655 (for jet A or jet A-1)). Once a batch is analysed and certified as aviation fuel a Refinery Certificate of Quality (RCQ) is issued. Further downstream of the refinery a Certificate of Analysis (CoA) can be issued by an approved laboratory for a batch of fuel (includes analysis of all parameters of the fuel specification, but not details of additives). Distribution Following manufacture, batch production and certification the fuel is moved to a holding tank (usually within the refinery, but not always) and from there it is released into the distribution system (part of the aviation fuel handling system). The distribution system may use a number of transportation methods, such as pipelines, road trucks, rail cars, river barges and seagoing (marine) ships. The system may also carry other types of fuels (e.g. diesel), in which case it is referred to as ‘non-dedicated’. After a batch of fuel has been distributed in a nondedicated system it has to be rebatched and a new analysis performed. This Recertification Test Certificate (RTC) verifies that the quality of aviation fuel has not changed. Whatever transport method is used during distribution, the fuel will eventually reach another storage tank. This may be at an airport or at an intermediate storage facility. In Figure 2, a dashed line in the distribution sector shows that it is possible for a fuel to be moved a number of times through a number of intermediate storage facilities. The risk of fuel cleanliness being compromised by particulate matter, water or microbial growth, is highest within this stage of the operation. The final movement of fuel from the distribution system to airport storage has to be via a single fuel grade dedicated system. Supply On arrival at the airport the fuel is delivered into a storage tank where its quality is assessed, after a period of settling. Once it is determined that it is acceptable3, it is available for use. Large uplifts of fuel into-plane typically utilise a hydrant servicer/dispenser vehicle, or cart, connected to an underground hydrant system, or a refueller having a tank for transporting fuel that is filled via a gantry or loading rack4. Airport practice adopted worldwide utilises filtration into-storage, out-of-storage and into-plane. Most of the information included in the rest of this publication applies directly to this operational area. Note 4: Smaller airfields may also utilise fixed refuelling points. Airport practice adopted worldwide utilises filtration intostorage, out-of-storage and into-plane Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 2 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 11 Chapter 3 Fuel cleanliness Key points of this chapter • The typical contaminants that impact on fuel cleanliness are free water, particulate matter and microbiological growths. • The majority of particulate contamination in the fuel supply and distribution system occurs as rust. • A predominance of iron oxides and silica was found in an API/IP survey of fuel cleanliness at major international airports. • Fuel contamination can cause potentially serious operational problems. • There is no industry consensus to a single definition of fuel cleanliness. • A range of ‘contamination limits’ exist for free water and particulate matter at various stages of aviation fuel handling systems. • An API/IP survey of international airports found that for the most part, airport fuel handling systems receive and handle only clean fuel, well within known quality limits. • The industry is evaluating alternative cleanliness assessment methods using electronic sensors for the detection of particulate matter and free water continuously, and in realtime, producing a quantitative, objective assessment of cleanliness. What are the contaminants? The typical contaminants5 that impact on fuel cleanliness are free water, particulate matter and microbiological growths. Free water: It is inevitable that dissolved water is present in aviation fuel, and at trace levels it does not cause any problems in aviation fuel handling operations. When the level of dissolved water exceeds the solubility limit of the fuel (e.g. as the fuel cools), free water precipitates, forming water droplets, see Figure 3. Free water may also be introduced into fuel by gross contamination from an external source (e.g. in marine deliveries or via leaking tank floating roof/cover seals). Bulk water can be removed from fuel by draining, but finely dispersed water droplets with very slow settling velocities can only be removed quickly by the use of a separation process – coalescence, see Figure 4. 1000 Water Conc. / ppmv Note 5: It should also be noted that there may be contamination of aviation fuel by other fuels, surfactants or additives used in other fuels, that are not ‘approved’ by the aviation fuel specifications. Such ‘cross-contamination’ may affect other properties of the fuel, but does not affect fuel cleanliness. It is only considered further in this publication in chapter 7, regarding the effects of such cross-contamination on the performance of filter/water separators. Note also effect of FSII on filter monitors (chapter 9). For further information see API 1595 Design, construction, operation, maintenance, and inspection of aviation pre-airfield storage terminals, or Joint Inspection Group (JIG) 3 Guidelines for aviation fuel quality control and operating procedures for jointly operated supply and distribution facilities. 100 10 1 0 20 40 60 80 100 120 Tem perature / C Figure 3: Water solubility in jet A-1 (from The Handbook of Aviation Fuel Properties (CRC Report No. 635), 2004, (average from large sample) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file3is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 12 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Fuel cleanliness Particulate matter: Particulate matter contamination can occur from several sources, including: • Pipeline, storage tank, ship or tank rust and scale (Fe3O4 and Fe2O3). • Product carry-over from ship cargos. • Ingress of airborne dusts such as sand, lime, gypsum etc. • Process salt from refinery salt driers, see chapter 4. • Sea salt from marine distribution. • Equipment component failure. The majority of particulate contamination in the fuel supply and distribution system occurs as rust. Table 1 lists a number of common particulate materials that have been found in fuel samples taken at airports. The examples given are a compilation of many individual results of analyses of contaminant samples obtained in the API/IP airport fuel cleanliness survey, described later in this chapter. Table 1: Examples of common minerals found in field samples The process of identification may begin with elemental analysis. In the case of a simple result in which, for example, only sodium (Na) and chlorine (Cl) are found, the conclusion would be rapidly reached that the contaminant comprises salt (NaCl) since there is only one material with that elemental composition. However, when an elemental analysis yields a number of elements, such as sodium (Na), aluminium (Al) and silicon (Si), the simplest conclusion that this indicates the presence of sand (silica – SiO2) and alumina (Al2O3) etc, may actually be incorrect. These elements are also components of more chemically complex materials, e.g. feldspars that are found in many soil types. In such circumstances, the contaminant analysis strategy must include a range of tests, including for instance X-Ray Diffraction, to unambiguously identify the nature of the particulate contamination. Element Crystalline phases Comments Al(OH3), -Al2O3 Many Al oxides and hydroxides are amorphous Calcium (Ca) CaCO3, Calcite, CaCl2 CaCl2 is often used in salt driers; sea salt Chlorine (Cl) Many as a chloride Chloride anion Aluminium (Al) Chromium (Cr) Should be trace Copper (Cu) Should be trace Iron (Fe) FeO wustite -Fe2O3 hematite Fe3O4 magnetite -FeOOH goethite -FeOOH akagonite -FeOOH lepidocrocite The form of rust and scale depends on the specific corrosion conditions Potassium (K) KCl Marine salt, minerals as silicate Magnesium (Mg) Should be trace, sea salt Manganese (Mn) Should be trace Sodium (Na) NaCI Salt, minerals as silicates Nickel (Ni) NiO Should be trace Phosphorus (P) Many Phospate anion SiO2 (quartz) Quartz: from sand or concrete as silicate minerals Sulfur (S) Silicon (Si) Sulfate anion, sulphide anion Titanium (Ti) Zinc (Zn) Should be trace The following were the findings from the API/IP airport fuel cleanliness survey described later in this chapter. Contamination compositional analysis found that the frequency of elements ranked in the following order: Fe >>Si >S = Ca >Al >Cl >Na = Cr >trace elements Fe was identified as a variety of oxides or hydrated oxides (rust and scale) which is to be expected in a distribution system made mostly of steel. Si was identified in almost all cases as quartz (SiO2) (sand). S was surprisingly common, indicating the presence of anaerobic bacterial action. Al and Ca are commonly associated with soil derived clay minerals. NaCl (salt) was found in a small number of cases. Clearly the predominance of iron oxides and silica in the field supports the use of such materials as test dusts in filter qualification testing. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 13 Handbook on equipment used for the maintenance and delivery of clean aviation fuel The predominance of iron oxides and silica in the field supports the use of such materials as test dusts in filter qualification testing Note 6: 1 μm = 1 thousandth of a millimetre. 70 μm is the average diameter of a human hair, but 40 μm is considered relatively large in the context of particulate matter contamination. Large particles (for instance those greater than 40 μm)6 readily settle out in storage tanks. This is because large particles have high settling velocities, as shown in Figure 4. Consequently smaller particles require some form of filtration to remove them, as their settling velocities are so low. 0,1 0,01 0,001 Stokesian Terminal velocity, m/s Figure 4 shows that 40 µm particles take 16 min to settle 1 m while 10 µm particles require nearly three hours to settle 1 m. When particulate matter is less than 10 µm, settling may never occur due to thermal circulation. 0,0001 0,00001 Water 0,000001 Iron Oxide, Rust Silica, Sand 0,0000001 0,00000001 0 10 20 30 40 50 60 70 80 90 100 Particle size, microns Rust, scale and silica particles have densities, hence settling velocities, an order of magnitude higher than water and so settle out much more rapidly on a size for size basis. Figure 4: Relative settling velocities for some common contaminants as a function of particle size in jet fuel Microbiological growths: Freshly distilled fuels from refineries are usually sterile due to the high temperatures of the processes involved. However, because micro-organisms naturally occur in air and water, fuel readily comes into contact with them in aviation fuel handling systems. Microbes survive and proliferate at the fuel/water interface. They live in the water phase but metabolise fuel as their source of energy. Three types of micro-organisms – bacteria, yeasts and moulds – can proliferate in water associated with fuels. Yeasts and moulds are collectively known as fungi. The most common types of microbiological contamination in aviation fuel are fungi and bacteria. Fungi may manifest themselves as slimy deposits on tank surfaces or other structures containing fuel. During fuel movements both microbes and the by-products of their growth (such as slimes) may spread into the bulk fuel. Microbiological activity can be found in aviation fuel handling systems where water has been allowed to accumulate undisturbed (e.g. pipeline and hydrant low points, filter vessel sumps). Regularly draining water from systems removes many microbes. Filtration may also remove this material but spores pass through most filters. In extreme cases of stagnant water bottoms, anaerobic bacteria such as Sulfate Reducing Bacteria (SRB) can occur, particularly on, or near, steel surfaces. Significant SRB activity is mostly found when sea water, a prime source of sulfate, contaminates fuel, but SRB are rarely found in large numbers. SRB activity is particularly problematic with uncoated steel tanks because acids produced are very corrosive. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file3is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 14 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Fuel cleanliness More detailed information on microbiological contamination can be found in: IATA Guidance material on microbiological contamination in aircraft fuel tanks, EI Guidelines for the investigation of the microbial content of petroleum fuels and for the implementation of avoidance and remedial strategies, ASTM D 6469 Standard guide for microbial contamination in fuel and fuel systems, and ASTM Manual 47 Fuel and fuel system microbiology: Fundamentals, diagnosis, and contamination control. Figure 6: ‘Leopard spotting’ caused by advanced microbiological growths on outer sock of filter Figure 5: Advanced microbiological growths at the fuel/water interface Micro-organisms cannot grow without the presence of free water, emphasising the importance of good aviation fuel handling system design (enabling water to effectively drain to low points within the system), and the implementation of regular dewatering procedures. Note that extremely small amounts of water can support millions of microbes. Why do contaminants need to be removed? Table 2 provides examples of the undesirable operational effects of contaminants. This is not an exhaustive list, but gives an indication of how serious fuel contamination can be. Table 2: Typical contaminants that can be introduced into aviation fuel and their operational effects Note 7: At fuel temperatures below the freezing point of water, ice crystallites can form in a wet fuel, potentially blocking on-board engine filters. Whilst most commercial aircraft have hydraulic heat exchangers fitted to the filters to overcome this problem, most military aircraft and some smaller civilian jets do not and for this reason a Fuel System Icing Inhibitor (FSII) is added to the fuel in some applications. Particulate matter • Blockage of fuel supply pipes and lines (distribution system, and on-board aircraft fuel supply system) • Equipment failure due to wear • Premature blocking of both aviation fuel handling system filters and aircraft engine filtersa • Additive depletion • Deposition in storage tanks Free water • Corrosion • Microbiological infestations • Engine flameout (fuel starvation from large water slugs) • Blocked aircraft engine filters due to ice formation7 Microbiological growths • Blockage of fuel supply pipes and lines (distribution system, and aircraft fuel supply system) • Premature blocking of both aviation fuel handling system filters and aircraft engine filters • Corrosion • Disarming of filter/water separators (FWS) • Biofilms on fuel sensors • Extensive ground time for microbial growth cleanup and treatment For brief details of aircraft engine filter ratings and aircraft engine tolerance to fuel contamination, see Annex B. a Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 3 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 15 Handbook on equipment used for the maintenance and delivery of clean aviation fuel How is fuel cleanliness defined? There is no industry consensus to a single definition for fuel cleanliness because of: • the lack of any universally accepted analytical protocols and test methods for the contaminants. • the lack of definition of negligible levels, and • the large number of fuel specification authorities. What are the contamination limits? There are no quantitative contamination limits for microbiological growths in aviation fuel handling systems. Limits taken from: • (UK) MoD Defence Standard 91-91 Turbine fuel, Aviation kerosine type, Jet A-1, NATO Code F-35, Joint service designation: AVTUR • ASTM D 1655 Standard specification for aviation turbine fuels • JIG Aviation fuel quality requirements for jointly operated systems (AFQRJOS) • MIL-DTL-83133E Turbine fuels, aviation, kerosene types, NATO F-34 (JP-8), NATO F-35, and JP-8+100 • MIL-DTL-5624T Turbine fuel, aviation, grades JP-4, JP-5, and JP-5/JP-8 ST • Canadian General Safety Board 3.23-2005 Aviation turbine fuel (Grades JET A and JET A-1) • IATA Guidance material for aviation turbine fuel specifications • ATA 103 Standards for jet fuel quality control at airports Note 8: IATA (International Air Transport Association), - the trade association for major airlines, working with major oil companies, aircraft engine manufacturers, and other stakeholders, issues this publication, that defines minimum standards to be met by fuel suppliers to ensure clean dry fuel is delivered to aircraft. See Annex C. Some limits for particulate matter and free water, applied at various stages in jet fuel handling systems, are given in Table 3, including their source (relevant specification or guidance issuing organisation). This is not meant to be an exhaustive list but an example of how variable the limits are. The origin of these limits is unknown but the industry has been comfortable with the fact that operating in this way for many decades has produced an excellent safety record. Table 3: Examples of contamination limits used within the jet fuel handling system Contaminant limit Location Refinery production Water Clear and bright Particulate (gravimetric) 1,0 mg/l Clear and bright Distribution Clear and bright system Airport intostorage Authority Def. Stan. 91-91, JIG AFQRJOS No quantitative limit for water ASTM D 1655 0,5 mg/l Kinder Morgan pipeline 1,0 mg/l MIL-DTL-83133E (JP8) US Air Force 1,0 mg/l MIL-DTL-5624T (JP4/JP5) US Navy 2,2 mg/l Canadian General Safety Board 3.232005 Clear and bright Into-plane Comments 30 ppm 1,0 mg/l Clear and bright 0,44 mg/l 15 ppm (maximum allowable) A2, B2, and G2 (Dry) After-fuelling check IATA Guidance Material Rejection limit for monthly equipment check Canadian General Safety Board 3.232005 ATA 103 Colorimetric interpretation of a gravimetric membrane. In certain parts of the World major airport operations follow either IATA Guidance material for aviation turbine fuel specifications (currently 5th edition)8 that incorporates the most stringent requirements of the major fuel specifications or ATA 103. The IATA Guidance stipulates that fuel cleanliness is to be assessed by the simple visual criterion of “clear and bright”. This is known as the fuel’s “appearance”. For further details of IATA guidance material see Annex C. More quantitative, but less timely, is the Gravimetric assay of fuel cleanliness. This requires controlled sampling of fuel through a special filter membrane followed by a laboratory assessment but, of course, this measures only the amount of particulate material present in the Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file3is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 16 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Fuel cleanliness fuel, i.e.- not any free water. Techniques used for the measurement of free water mainly rely on various field assessment methods, some of which are described in Annex D. Note 9: The Energy Institute was formed in 2003 by the merger of the Institute of Petroleum (IP) with the Institute of Energy. IP branding of the aviation fuel handling portfolio was retained until 2007, but has now been replaced with EI. Note IP designation continues for test methods. API/IP9 airport fuel cleanliness survey To gauge how realistic some of the particulate matter contamination limits actually are, and to check target levels for filtration specifications, the API supported an IP survey of airport fuel cleanliness in 1995. Although that was more than a decade ago the data produced remain unique. The work was presented in the public domain10. Twenty airport locations distributed around the world (chosen to be representative of the variety of operational environments) were surveyed for particulate matter contamination levels in jet fuel. At each airport a sample was taken from the upstream (dirty) side of filters in the into-storage, out-of-storage and into-plane positions. Because only single data points were taken for each sample point at each location, the data are best described as a ‘snap-shot’ of the particulate matter contamination likely to be encountered. Nevertheless, a useful data set (for 18 locations) was produced with the following findings: Note 10: See Proceedings of the 7th International Conference on the Stability, Handling and Use of Liquid Fuels (IASH), A survey of solid contaminant types and levels found in a range of airport fuel handling systems, V.B. Hughes and P. D. Rugen. • Average into-storage particulate matter contaminant loading: 0,12 mg/l • Average out-of-storage particulate matter contaminant loading: 0,11 mg/l • Average into-plane particulate matter contaminant loading: 0,07 mg/l The averages appear to be very low and well within the previously described gravimetric limits for jet fuel. For into-storage, the highest value was 0,34 mg/l (see Figure 7A) which is still within the “notification” limit of IATA Guidance for into-plane fuel quality. Undoubtedly there may be times when systems fail, and fuel with excessive contaminant loading is encountered, but the survey suggests that this is an unusual circumstance. For the most part, airport fuel handling systems receive and handle only clean fuel, well within known quality limits. Figure 7A: Into-storage particulate matter contaminant loading 0,35 0,3 mg/l 0,25 0,2 0,15 0,1 0,05 0 Location R Location P Location Q Location N Location O Location M Location L Location K Location J Location I Location H Location F Location E Location D Location C Location B Figure 7B: Out-of-storage particulate matter contaminant loading 0,6 0,5 mg/l 0,4 0,3 0,2 0,1 0 Location R Location Q Location O Location M Location N Location L Location K Location J Location I Location H Location G Location F Location E Location C Location B Location A Figure 7C: Into-plane particulate matter contaminant loading 0,3 0,25 mg/l 0,2 0,15 0,1 Interestingly, the data indicated that the least demanding point of filtration at some airports could well be outof-storage, which feeds both hydrant systems and refuelling trucks, as shown in Figure 7B. Many locations returned similarly low levels of contamination into-plane (Figure 7C, note change of X axis), but a few indicated significant increases in contamination at this point, most likely due to re-contamination of the fuel by the hydrant. 0,05 0 Location Q Location P Location O Location M Location N Location L Location J Location K Location I Location F Location H Location C Location E Location B Location A Figure 7A,B,C: Particulate matter contaminant loading data (gravimetric contaminant loadings per ASTM D 2276) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 3 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 17 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Electronic sensors for detection of particulate matter and/or free water Within the distribution system, fuel cleanliness levels are often agreed between interested parties and therefore not always standardised. However, the growing costs of clean-up at airports mean that increasingly there are pressures on distribution operators to use filtration and cleanliness practices similar to those used at airports. Refineries supplying to Def. Stan. 91-91 or AFQRJOS now meet a gravimetric limit of 1,0 mg/l (by IP 423 or ASTM D 5452). Some refineries include filtration in their processing to ensure this limit is met. All companies involved with aviation fuel handling from refinery to aircraft are encouraged to apply the cleanliness controls recommended in this publication. For into-plane applications the quality and cleanliness of aviation fuel is not negotiable. The aviation industry has used the gravimetric and appearance test methods from its very earliest beginnings. There is no doubt that the use of these methods coupled with very conservative limits and well specified procedures to achieve them, have given the industry the very highest levels of confidence in supplying fuel that is fit-for-purpose. Due to the ever present possibility that these procedures may break down and developments in sensing technology, the industry is evaluating other cleanliness assessment methods. The EI has also published EI 1598 Considerations for electronic sensors to monitor free water and/ or particulate matter in aviation fuel, which provides recommended minimum performance requirements for electronic sensors that can detect low levels of particulate matter and/or water in aviation fuel in mobile applications (into-plane). A variety of technologies may be able to meet these requirements. Such electronic sensors will detect particulate matter and/or water continuously and in real-time, producing a quantitative, objective assessment of cleanliness. So what should I do about fuel cleanliness? It is recommended that operators have procedures in place for: • the assessment of fuel cleanliness, • the actions required if agreed fuel cleanliness limits are exceeded (these may include a lower ‘notification limit’ and a higher ‘rejection’ limit), and • the maintenance of fuel cleanliness through the appropriate use of quality assurance equipment and procedures…..the subject of the remainder of this publication. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file3is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 18 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Fuel cleanliness Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 3 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 19 Chapter 4 Description of components This chapter is intended to provide a general description of the components used for fuel cleanliness control, especially those that are within the scope of EI publications. Table 4 highlights certain design features of components within the scope of EI publications. Table 4: Design features of components used for fuel cleanliness control Component EI spec Particulate matter removal Dispersed water removal Bulk water removal Typical location applied FWS Type S EI High 1581/1582 capacity Intermediate Low capacity capacity Into and out of airport storage FWS Type S-LD EI Low 1581/1582 capacity Intermediate Low Out of airport storage, Downstream of a microfilter FWS Type S-LW EI High 1581/1582 capacity Low Into-plane only None Filter monitor EI 1583 (50 mm, 2 in.) Low capacity Low capacity Blocks filter Into-plane (refueller and hydrant servicer) Filter monitor EI 1583 (150 mm, 6 in.) Intermediate capacity Intermediate Blocks capacity filter Into-plane Microfilter EI 1590 High capacity None None Upstream of FWS Dirt defence filter EI 1599 Low capacity None None Into-plane (refueller and hydrant servicer) in conjunction with electronic sensor Electronic sensor EI 1598 None None Downstream of filter vessel intoplane None Note: The filters listed above have to be housed in a filter vessel. The recommended minimum requirements for vessels are included in EI 1596 Design and construction of aviation fuel filter vessels. element Filter/water separator (FWS) (EI 1581 and EI 1582) Term used to describe the ‘disposable’ part of a filter (for either a filter monitor, filter/coalescer, separator, microfilter or dirt defence filter). Also referred to as a cartridge. A FWS is a vessel containing two types of elements: filter/coalescers and separators, see Figures 8 to 11. A FWS is designed to continuously remove particulate matter and water from aviation fuel to levels acceptable for servicing modern aircraft. As the workhorse of aviation fuel filtration, the FWS can be used in any filtration application anywhere in the fuel manufacturing, distribution and supply system. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file4is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 20 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Description of components Filter/coalescer elements Separator elements Flow: in-to-out Flow: out-to-in Pleated filter media Wound coalescer material TeflonTM or synthetic screen Cotton sock Inlet Outlet Sump drain Figure 8: Schematic of a vertical filter/water separator Pressure relief valve Sample probe Automatic air eliminator Differential pressure gauge Separator elements Spider plates Manual drain Filter/coalescer elements Figure 9: Illustration of a horizontal filter/water separator Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 4 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 21 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Figure 10: Cross-sections of current models of filter/coalescers rated flow Is the flow per inch of length of the element below which the limits of EI specifications can be met, see also chapter 12. Firstly fuel passes through a combined filtration and water coalescence element (in-to-out flow filter/coalescer), where particulate matter is filtered out and finely dispersed water droplets are coalesced into larger droplets which easily settle out of the fuel under gravity. Secondly, fuel passes through a separator element (outto-in flow separator), which is usually a simple water-repelling Figure 11: Separator elements (hydrophobic) screen. The separator element ensures any water droplets are not carried downstream in fuel. Coalesced water drops settle out of the fuel rapidly in the space between these two types of element and accumulate in the sump of the vessel, where bulk water can be drained off. Vessels usually contain more than one of each element type. Each element has a maximum recommended flow rate (rated flow). This may change dependent on the application. It is not unusual to find vessels with over 20 filter/coalescer elements (fewer separators) fitted. The length of filter/ coalescer and separator elements can vary, up to 1 420 mm (56 in.). The FWS can be oriented either vertically or horizontally. Figure 12: Out of storage vertical filter/water separators Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file4is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 22 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Description of components Filter monitor (EI 1583) A filter monitor is a vessel containing one type of element that contains water absorbent media called super-absorbent polymer (SAP) (similar to that used in disposable diapers). The intention of the design is to remove small amounts of particulate matter and dispersed free water from aviation fuels to levels acceptable for servicing aircraft. It is also intended that in service, a filter monitor system will restrict the flow of fuel before its capacity for particulate matter and/or water removal is exhausted. On contact with water, whether finely dispersed or as bulk water ‘slugs’, the water absorbent media form a gel that swells to fill the element, see Figures 13 and 14. This causes the fuel flow to reduce and/or the differential pressure to rise. In extreme situations the gelling process may shut off the flow completely. Such devices are intended to ‘activate’ when something is dramatically wrong in the aviation fuel handling system, i.e. gross bulk water contamination of fuel. However, they are also designed to be able to remove low levels of particulate matter and dispersed water over a longer time period, without the need for frequent replacement (change-out). Filter monitors can be of vertical or horizontal orientation. The filter monitor elements are typically 50 mm (2 in.) nominal diameter with out-to-in fuel flow format (see Figure 13), or 150 mm (6 in.) nominal diameter with outto-in or in-to-out fuel flow format. Figure 13: Cut-away of a two inch nominal diameter out-to-in flow filter monitor element Filter monitors are sometimes referred to as ‘fuses’. This is inappropriate, however, as a filter monitor can fail (in terms of its ability to remove free water) and still allow the passage of fuel, as can a FWS. An electrical fuse always ‘fails’ to safety, by preventing the passage of further current. At the time of publication of EI 1550, the only filter monitors currently available are those qualified to API/ EI 1583 4th edition (or earlier editions). In November 2006, the 4th edition was superseded by EI 1583 5th edition with API withdrawing from the joint standard. The latest ‘current’ edition of the specification is EI 1583 5th edition. At the time of publication of EI 1550, no manufacturer had qualified a filter monitor to EI 1583 5th edition. Unless otherwise indicated, all references to EI 1583 refer to the 5th edition. Super Absorbent Polymers (SAP) + Water Viscous Gel Figure 14: Principles of water absorbent media Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 4 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 23 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Figure 15: Beakers of super-absorbent polymer in powder form, before and after the addition of water to beaker B. Microfilters are sometimes referred to as micronic filters or prefilters. deep-bed filtration A filter with multiple layers of fibres (threedimensional), see Figure 17. For further information on nominal rating, see Annex E. Microfilter (EI 1590) A microfilter is a vessel containing elements that continuously remove, from aviation fuels, particulate matter of a nominal minimum particle size (element nominal rating in μm). The vessel may have a vertical or horizontal orientation. A schematic of a vertical microfilter is shown in Figure 16. This type of filter utilises a single-pass flow format and elements comprising fibrous media that constitute a ‘deep-bed’ filtration process. The filter medium does not restrain the particles absolutely. Particles larger than the maximum pore size are held on the surface of the medium, but smaller particles can, and do, enter the pore system. Once inside the medium some particles may be large enough to block internal pores. Other particles may adhere to the surfaces of the medium due to physico-chemical forces. These latter particles are typically much smaller than the average pore dimensions. Thus it is possible for a fairly coarsely graded deep-bed filter to remove particles much smaller than would have been expected from porosity considerations alone, see Figure 17. Consequently these filters can only be described as having nominal performance ratings. Air eliminator Pressure relief valve Microfilter elements Pressure differential gauge OUT IN Drain valve Figure 16: Schematic of a vertical microfilter Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file4is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 24 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Description of components The blocking of internal pores by discrete particles or aggregates of adsorbed particles leads to an increase in the pressure drop across the medium (differential pressure). As the differential pressure increases, or if there are any sudden pressure fluctuations, the transmission of captured particles (especially of the adsorbed type) becomes more probable and so the performance of such deep-bed filters is often assessed by measuring filtrate quality under defined flow and pressure drop conditions. Tortuous flow path Large particle of particulate matter captured on surface Particulate matter captured in matrix Adsorbed particulate matter Figure 18: Cross-section view of a microfilter Figure 17: Fibrous media of a deep-bed filter Dirt defence filter (EI 1599) A dirt defence filter comprises a pressure vessel containing one or more dirt defence filter elements. They may be oriented vertically or horizontally. They are different to microfilters in that they are qualified at their maximum flow rate. They are intended to remove low levels of particulate matter from aviation fuel, and restrict the flow of fuel before their capacity for particulate matter removal is exhausted. Dirt defence filters are only intended for use intoplane in conjunction with water removal or water detection devices that will ensure free water content in fuel is acceptable. At the time of publication of EI 1550 dirt defence filters were not recognised by any of the industry operational guidance documents. Filter vessels (EI 1596) Filter vessels are pressure vessels incorporating an inlet and outlet for fuel flow. They are designed to house filter elements (FWS, filter monitors, microfilters or dirt defence filters). They may be used in fixed or mobile applications, and oriented horizontally or vertically. Electronic sensors (EI 1598) Electronic sensors are devices for the detection of particulate matter and/or free water in aviation fuel. They can be used on into-plane fuelling equipment in conjunction with filtration equipment, or may be considered for use in airport depot fuel systems. Other components (not within the scope of EI publications) There are many other types of equipment/components in use in aviation fuel handling systems that are not covered by EI publications. Very often the use of such equipment is for specific applications, and may sometimes be used on a temporary basis to achieve a specific fuel quality property. This publication identifies a number of such components, see Table 5, but does not provide further details. They are included here to provide the operator with information on the broader use of such technologies. The list below is not exhaustive, but includes those devices/technologies most likely to be encountered in aviation fuel handling systems. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 4 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 25 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Table 5: Equipment/components in use in aviation fuel handling systems not covered by EI publications Component Description Common use Silica gel A granular material that has high affinity for both dissolved and free-water. Often supplied with a colourant to indicate when the material is exhausted (blue to pink). As a very expensive material it is usually used in laboratories or in applications where components need to be kept away from any level of humidity. Salt drier Sodium chloride crystals are able to absorb huge amounts of free and dissolved water. Salt driers may be units measuring 10 m or more in height and need to be regularly monitored for condition. Used in refinery wet processing of aviation fuels as a dehydration unit, especially upstream of a clay treater (see below). Hydrocyclone Passive hydromechanical devices that induce a cyclonic flow in a system. Capable of removing coarse (>40 μm) particles and water droplets. A low cost, efficient component for removing the bulk of a heavily contaminated fuel. On large pipelines, especially downstream of ship cargo. Bag filter More refined than the hydrocyclone but still less sophisticated than filtration components covered by EI publications, bag filters can be used to remove coarse contamination quickly and cheaply. 20 X 250 Hollander Weave stainless steel or monel metal mesh filters can be capable of filtration down to 40 μm. These can be used to reduce the contaminant loading on finer filtration components in any applications where grossly contaminated fuel is encountered anywhere from the refinery to the airport receipt facility. Hay pack Vessels filled with wood fibre (excelsior), wood shavings or polypropylene mesh. Intended for removal of large volumes of bulk water. May be used at marine receipt facilities where the threat of bulk water contamination may be high. Also sometimes used to prevent water contamination entering clay treaters. Magnetic rods A basic system using rods that are magnetised such that they attract ferromagnetic particles, (Fe), from the fuel. They require regular cleaning to remove any attracted particles. Sometimes used in conjunction with microfilters at pipeline receipt points (old steel unlined pipelines) from sea vessel receipt. Clay treater A large vessel containing Attapulgus clay, either in bulk or in replaceable cartridges. This special clay adsorbs surface-active agents and colour bodies in the fuel which are not otherwise removable. For further details see Annex F. Refineries and pipeline breakout stages. Most likely of the components included in this table to be found at airports (into-storage), especially when supplied by multiproduct pipelines. Found most frequently in the US. Strainer A gauze or basket to prevent large (visible) debris passing downstream. In the hose end connector between the into-plane filtration on refuelling equipment and the aircraft tank. Note: there are a few potentially vulnerable components such as hose couplings and the hoses themselves, after final intoplane filtration that in extreme circumstances may produce debris. Also upstream of pumps anywhere in the distribution system. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file4is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 26 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Description of components Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 4 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 27 Chapter 5 Relating EI specifications to end use of filters How do specifications relate to end use of filters? Note that this process does not currently apply to electronic sensors for particulate matter and/ or free water detection. Although EI 1598 includes minimum performance requirements the 1st edition does not include Qualification Tests. Electronic sensors cannot, therefore, be qualified to EI 1598. Figure 19 shows the recommended process that should be followed in the adoption of filter components used in aviation fuel handling systems. EI Specification Testing Manufacturer (Design and Development) Media Selection Knowledge feedback Does not meet specification requirements Not Recommended Qualification Does not meet operational requirements Field Evaluation Meets operational requirements User Approval Non Qualified Equipment Not Recommended Knowledge feedback Use Figure 19: Relationship between EI specifications and end use of filters Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file5is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 28 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Relating EI specifications to end use of filters Why is this process recommended? This process has been demonstrated over many years to provide users with confidence in the suitability of components used to control fuel cleanliness in aviation fuel handling systems. The key points for each of the steps are as follows: Specification EI filter specifications are not complete product specifications. They provide only general mechanical requirements, some minimum performance requirements and laboratory qualification tests. • Provides minimum performance requirements for selected aspects of performance only, under laboratory conditions. • Provides series of Qualification Tests for a model of filter. Due to their destructive nature, Qualification Tests cannot be used for every component testing of production filters. • Laboratory testing alone cannot replicate all operating and environmental parameters to which filters will be exposed when in use. • Provides consistent methods for conducting tests. • Prepared by technical experts from industry stakeholders (including filter manufacturers and major users), based on consensus agreement. • Incorporates findings from industry research (e.g. that funded by the EI, see next chapter), that provided by manufacturers, and experience from users. • Should never be considered as restrictive to new innovation/manufacturers’ developments. • Reviewed for continued technical validity at least every five years. Manufacturer • Chooses whether to qualify a model of filter in accordance with specification requirements. • Is responsible for the development of suitable prototype filters, that in addition to meeting specification requirements, will be suitable for the intended application. • Undertakes in-house testing. • Provides feedback to EI regarding specification requirements. • Notifies potential users that a design is to undergo qualification testing. Qualification • Is the process of demonstrating that a filter successfully meets, or exceeds, all of the mandatory test requirements of the relevant specification. • Some specifications require that the laboratory qualification testing is ‘witnessed’ by a purchaser’s representative. • Manufacturers may also choose to invite other industry stakeholders to their qualification testing. • EI operates a certification program to provide witnesses for filter qualifications. • The inability of a filter to successfully meet all of the mandatory test requirements leads to a filter redesign, or if the specification test is new, a re-evaluation of the test requirements by EI. • The qualification process results in a qualification report from the manufacturer, that is confirmed as being accurate by the witness. • If the qualification report is acceptable to the purchaser (user) the manufacturer can claim that their filter is ‘qualified to the relevant specification’. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 5 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 29 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Field Evaluation • It is recommended by EI that users evaluate the field performance of a newly qualified model of filter. • Laboratory testing alone cannot assess the long-term durability, mechanical integrity and performance of filters in aviation fuel handling systems. • Is required to help demonstrate that a filter is ‘fit-for-purpose’ or ‘suitable for the intended application’. • Users may choose to undertake this process at a number of selected locations, that offer minimal risk and maximum component monitoring capabilities. • If a filter model is not deemed to be suitable for use as a result of field evaluation (does not meet operational requirements), it may result in a filter redesign, or if the specification test is new, a re-evaluation of the test requirements by EI. User approval • It is only user companies that finally decide if a specific model of filter is acceptable for their use. The EI does not issue ‘approvals’. • The user approval process is usually unique to each user company. • Requires the user to recognise that the ‘qualification’ is valid. • Some users may choose to issue approvals without undertaking field evaluation of qualified filters. This is not recommended. Non-qualified filters • The use of filters that are within the scope of an EI specification, but are not qualified in accordance with one, is not recommended. • For filters outside the scope of EI specifications it is recommended that the user undertakes a complete programme of field evaluation to determine that the filter is suitable for its intended use. Use • Requires there to be no variance between filters from the production line, and the model/ design that was qualified. See also chapter 15. • Filters should always be used in accordance with manufacturer’s recommendations. • Feedback received from users of their operational experiences may lead to a re-evaluation of specification test requirements by the EI. EI filter specifications are not complete product specifications. They provide only general mechanical requirements, some minimum performance requirements and laboratory qualification tests. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file5is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 30 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Relating EI specifications to end use of filters Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 5 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 31 Chapter 6 Laboratory testing requirements This chapter provides information on the laboratory testing requirements included in EI specifications for filters. It is intended to make potential users aware of the scope of laboratory testing to which a qualified filter model/design has been subjected. Introduction As noted in chapter 5 EI 1598 does not include laboratory testing requirements, so currently there are no agreed tests for electronic sensors. The purpose of ‘qualifying’ a filter model/design, in accordance with qualification test protocols included in EI publications, is to confirm to a potential user that a particular filter design is capable of meeting selected performance requirements under laboratory conditions. It should therefore be understood that to determine whether a filter is ‘fit-for-purpose’ or ‘suitable for its intended application’ there may be other parameters that require further testing/field evaluation. See also ‘What types of test are not currently specified in EI publications and why?’ later in this chapter. In devising test protocols for components, there are a number of issues to overcome or accommodate to reflect the variety of operational needs. As shown in the previous chapter, test protocols develop over time in response to experience and new technology. They need to be generally applicable (to avoid frequent protocol revision programmes, and to not be excessively onerous), but also comprehensive (to ensure that they reflect selected operational conditions). These two aspects conflict and so the protocols included in EI publications (described in this chapter) reflect a compromise that produces a minimum level of testing agreed across the industry after many hours of stakeholder review and technical debate. The EI publications also contain minimum performance limits for a specific range of tests applicable to filter components – but – they are only selected parameters and as such should never be assumed to be absolute in terms of operational applicability. General testing features A model/design of filter is tested by subjecting it to standard fuel contaminants (defined later) and quantitatively measuring its responses. However filters are also tested for their mutual effects on the fuel (compatibility) and structural stability. The settling velocities for typical contaminants in Avgas (in comparison with Figure 4 for jet fuel) are substantially higher. Hence, separation of contaminants is easier in Avgas. Testing with jet fuel therefore represents worst case. Single-element and full-scale testing: Test protocols are identified as being either singleelement or full-scale. Single-element testing refers to testing being undertaken on the minimum number of elements for the filter system to operate. In the case of filter monitors, microfilters, and dirt defence filters this is one element only. In the case of filter/ water separators, a single-element test requires testing of a combination of one filter/ coalescer and one separator. Full-scale testing refers to testing being undertaken on a vessel filled with a number of elements. EI 1590 and EI 1599 only include single-element tests. Full-scale testing is more relevant to water removal performance where the flow patterns through multiple elements in a vessel, and fuel/water residence time in the vessel, play a significant role in water removal efficiency. Test fuel type: Due to safety issues with the handling of low flash point fuels, almost all testing is carried out only using jet fuels, with an acceptance, based on industry experience, that the measured performance of filters in jet fuels translates across to filter performance in low flash products such as aviaton gasoline, jet B etc. However, compatibility of filters and fuels, is tested across the whole range of fuel types due to noted solvency differences (see following). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file6is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 32 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Laboratory testing requirements Test fuel composition: Test fuels are procured locally by the test facility, and are required to meet jet A or jet A-1 specifications. Clay treatment of the test fuel is required to return the fuel (which could be from a number of sources), to a baseline condition in terms of its surface activity – an important property in terms of contaminant stability and filterability/ separation. Jet fuels contain molecular components, either added as additives to enhance certain fuel properties, or in trace amounts from their source, or processing. To reflect a severe operational environment there are a number of additives that are added to the test fuel to challenge the performance of the component. These additive combinations have varied over the years but those that apply currently are shown in Table 6. Reference to the individual EI publications gives the actual levels and combinations of these additives in test fuels. No aviation gasoline additives are included in component testing. Table 6: Additives used in EI test protocols Test fuel type Civilian (C) Category Military (M) Category M+100 Category Additive Dosage level Stadis 450 (a static dissipater additive) 1 mg/l DCI4A (a corrosion inhibitor/lubricity enhancer) 15 mg/l Stadis 450 (a static dissipater additive) 2 mg/l DCI4A (a corrosion inhibitor/lubricity enhancer) 15 mg/l FSII (an icing inhibitor – diethylene glycol monomethyl ether) 0,15% v/v The additives for M category and +100 additive (a thermal stability enhancer) 256 mg/l Test particulate: Current test protocols require the use of a test ‘dust’ (intended to simulate particulate matter found in aviation fuel handling systems) that is traceable to an ISO standard (ISO 12103-1). The particular test dust is a silica material coded A-1 (Ultrafine) with a particle size distribution given in Figure 20. ISO 12103-1 – Road vehicles - Test dust for filter evaluation - Arizona test dust ISO 12103, A-1 Ultrafine Test Dust 30 Differential Volume % 25 20 15 10 5 0 0 2 4 6 8 10 Particle size, microns 12 14 16 Figure 20: Particle size distribution for ISO 12103, A-1 Ultrafine test dust Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 6 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 33 Handbook on equipment used for the maintenance and delivery of clean aviation fuel With a particle size distribution in the range 1-15 μm, this dust is ideal for testing aviation fuel filters rated within that range. Note 11: EI Research Report The effects of shear and fuel chemistry on the particle size distribution of Fischer I-116 and Elementis R9998 red iron oxides and ISO Ultrafine silica test dusts in jet fuels, V.B. Hughes & P.D. Rugen. Available from the EI library. Another dust, a red iron oxide identified as Elementis R9998, is added to the A-1 test dust (in a 10:90 mass ratio respectively) or, as in the case of 1,0 μm-rated microfilters, used on its own. R9998 is primarily a paint pigment and as such is not traceable to a standard. However, its particle size distribution was measured through EI-funded research11 during the development of API/EI 1581 4th edition, and was found to be largely sub-micronic when fully dispersed, see Figure 21. (Note, Hitec 580 is another type of corrosion inhibitor, and is similar in terms of its composition to DCI4A.) As can be seen from Figure 21, R9998 is a relevant test dust for filters claimed to have very small particle size removal ratings. Because of its colour it is also very useful for tracing weaknesses in all filters when testing (passage of the test dust downstream of a filter under test is readily visible). The 90:10 mass % A-1 Ultrafine/R9998 test dust mixture is the standard ‘particulate’ challenge in EI filter specifications. 20 18 16 14 % in range Typically filter manufacturers undertake qualification testing using their own test rigs. It is not a requirement of the specifications for a filter to be qualified on multiple test rigs, or at a test facility appointed by the user. 12 10 8 6 4 2 0 0.1 1 Size, microns 90% Ultrafine/ 10% R9998 10 100 R9998 Figure 21: Particle size distributions of test dusts in jet fuel dosed with Stadis 450, Hitec 580 and a model surfactant Material compatibility: Any component that is to be used in aviation fuel has to be shown to have no effect on the quality of the fuel and not be affected by exposure to the fuel – they must be mutually chemically and physically compatible. Compatibility testing is a mandatory requirement of each EI specification. Test Rig: Filter qualification requires testing on a test rig that has the features shown schematically in Figure 22. Although each EI specification contains specific requirements for the test rig, Table 7 highlights some of the general key features. Repeat Testing: It is a requirement of EI 1583, and EI 1599 (both applicable to filters typically used in into-plane applications), for qualification tests to be repeated. Results from the repeat tests are required to be consistent. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file6is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 34 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Laboratory testing requirements Bypass Heat Exchanger Fuel Storage Tank 2 Clean up Clay Filter vessel Bypass Flowmeter Fuel Storage Tank 1 Bypass Recommended additive injection points differential pressure gauge Hopper Temperature probe TEST VESSEL Solid contaminant injection Pump Upstream sampling point Water injection Downstream sampling point Fast-closing shutdown valve Figure 22: Schematic of typical test rig used in filter qualifications Table 7: Key features of filter test rigs Fuel volume Minimum fuel volume is governed by the requirement for a single pass test (fuel only passes filter once, not recirculated) and twin fuel storage tanks are required to accommodate this. Pump and flow meter Pump is required to be capable of achieving a minimum of 115% of the full rated flow of the filter being tested without an excessive temperature rise. Flow to be measured with a calibrated meter. Heat exchanger Test fuel temperature should not exceed 30 °C and should be maintained at a consistent temperature during the course of the test. Contaminant injection (free water or test dust) Required to be injected continuously and evenly throughout the test. For dispersed water tests, the water is injected at a point upstream of the main pump and this will produce fine water droplets, considered to be consistent with those found in aviation fuel handling systems. Particulate is injected at a point upstream of the test vessel as well-mixed slurry from a hopper into the test fuel. Fuel clean-up To maintain test fuel cleanliness, or return the fuel to baseline condition, fuel may be passed through a suitable downstream filter/clay treater. Further treatment may be required to remove FSII. Sampling points Test fuel samples are taken by upstream-facing, probe-type sampling devices situated within ten pipe diameters of the outlet or inlet of the test vessel. Test stand A test vessel to house specific filter element(s), incorporating a means for fuel to by-pass the filter being tested, differential pressure measurement. Fast-operating shutdown valve Required to operate within four seconds to simulate rapid valve closure experienced in fuelling operations, and pump start up. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 6 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 35 Handbook on equipment used for the maintenance and delivery of clean aviation fuel What types of test are not currently specified in EI publications and why? As noted at the start of this chapter test protocols are required to be generally applicable but also comprehensive. It is therefore not possible to include tests covering every possible operational parameter in qualification testing. The selected aspects of performance that are tested, are those for which consensus has determined there to be the greatest need. Several performance issues that are not currently covered within the publications referred to, as they are not perceived by the industry to be significant and are more appropriately addressed on an operational basis, are: • Inclusion of more stop/starts of a severity that simulates valve closures that may introduce pressure surges in the into-plane fuelling system. • Extremes of operational temperature. • Vibration (especially for on-vehicle applications). The above issues, and others yet to be identified, may be considered in future test protocols, subject to sufficient research that demonstrates them to be relevant, and that provides valid test protocols. Each of the EI specifications highlights that users can specify any additional tests they consider relevant for their specific application(s). Any users that obtain test data or field experience for parameters not currently covered by EI specifications, are encouraged to submit details to the EI (www.energyinst.org.uk/filtration). Test protocols for specific types of filter The rest of this chapter summarises the test protocols described in EI 1581, 1583, 1590 and 1599. These form the basis for qualification testing of those types of filter. For further specific details, the reader is referred to those publications. Filter/water separators (EI 1581) Single-element Test: A combination of one new filter/coalescer element and one new separator element is subjected to a continuous test sequence summarised in Figure 23. After a preconditioning step in which the elements are exposed to the test fuel under low flow conditions, the flow rate is increased to the rated flow. The elements are then subjected to (‘challenged’ with) dispersed water and test dusts under specific conditions. Key points of the EI 1581 single-element test protocol: • Establishes the rated flow of the element. • Includes low level water removal, followed by test dust removal, further low level water removal over an extended period, by the filter loaded with test dust, and finally a short period of ‘high’ level water removal (for Type S and Type S-LD only). • For Type S-LW, the final short period of water challenge is 0,5%. • Test incorporates 13 stop/starts. • Effluent fuel samples are required to be taken at various times during the test. • At the end of the test the elements are visually assessed and disposed of. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file6is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 36 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 3.0% water removal Preconditioning Contaminant challeng 0,01% water removal Laboratory testing requirements 19 mg/l test dust filtration 0,01% water removal Rated Flow Flow spikes represent the timings of 4 sec stop/starts 10% Rated Flow 30 60 90 120 150 180 210 240 270 300 Time/minutes Figure 23: Schematic of the EI 1581 single-element test protocol The tested elements have to meet the minimum performance criteria specified in EI 1581: Minimum performance criteria specified in EI 1581 for FWS ASTM D 2276 Test method for particulate contaminant in aviation fuel by line sampling IP 216 Determination of particulate contaminant of aviation turbine fuels by line sampling ASTM D 3240 Standard test method for undissolved water in aviation turbine fuels Effluent fuel samples shall not exceed: a. Total solids content of 0,26 mg/l (1,0 mg/gal.) by ASTM D 2276/IP 216. b. Free water content of 15 ppmv by ASTM D 3240. c. Media migration of 10 fibres/l (40 fibres/gal.). The capacities of the elements in achieving these performance limits are different according to the type of element (Type S, S-LD or S-LW). A summary of these differences is given in chapter 7. Full-scale Test: Following a successful single-element test, a full-scale test is carried out using multiple elements in a vessel operating at a flow rate representative of that experienced in service. The continuous full-scale test sequence is summarised in Figure 24. The fullscale test confirms that the water and particulate removal of a filter/water separator (the vessel containing multiple elements, as used in the field) is in accordance with minimum performance limits included in EI 1581. The performance requirement for the singleelement test and the full-scale test is the same. Whilst the full-scale test is of a shorter duration, larger volumes of fuel are used. This is therefore the only test that is performed with the test fuel flowing in recirculation. Only flow rates up to 9 500 lpm (2 500 gpm) are within the scope of EI 1581. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 6 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 37 19 mg/l test dust filtration 3.0% water removal Contaminant challenge 0,01% water removal Preconditioning Handbook on equipment used for the maintenance and delivery of clean aviation fuel 0,01% water removal Rated Flow Flow spikes represent o timings of 4 second Stop/Starts 10% Rated Flow 30 60 90 120 150 180 210 Time/minutes Figure 24: Schematic of the EI 1581 full-scale test protocol Key points of the EI 1581 full-scale test protocol: • Confirms that the system as a whole meets minimum selected aspects of performance. • Confirms the rated flow of the elements. • Includes the same water and test dust challenges, but of shorter duration, as the singleelement test protocols. • Test incorporates eight stop/starts. • Effluent fuel samples are required to be taken at various times during the test. • At the end of the test the elements are visually assessed and disposed of. Filter monitors (EI 1583) The qualification of filter monitors is based on a large number of single-element tests, and two full-scale tests. The mandatory single-element tests are summarised in Table 8, with the fullscale tests included in Table 9. The tested elements have to meet the minimum performance criteria specified in EI 1583: Minimum performance criteria specified in EI 1583 for filter monitors Effluent fuel samples shall not exceed: 1.Media migration - 10 fibres/l and less than 0,26 mg/l (1,0 mg/gal.) debris. (No indication of SAP migration) 2.Free water - 15 ppmv 3. Total solids - 0,26 mg/l (1,0 mg/gal.) average - 0,5 mg/l (1,9 mg/gal.) maximum 4.Appearance - the effluent fuel shall be clear and bright EI 1583 5th edition also includes suggestions for additional optional single-element test procedures. These do not form part of qualification testing. The test procedures have not been sufficiently researched to be able to confirm their suitability or to define performance limits. The topics covered are single-element water removal performance when exposed to low temperature, repeated freeze/thaw cycles and repeated stop/starts. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file6is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 38 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Laboratory testing requirements Table 8: EI 1583 Mandatory filter monitor single-element test protocols Qualification Test Number Comments 1 Test to confirm limited filter material migration and initial differential pressure across element. Intended to ensure integrity of element when exposed to fuel flow and pressure, and effluent fuel quality. 2 50 ppm water challenge at rated flow 12 50 ppm water challenge at 10% of rated flow 50 ppm ensures a practical working capacity of the filter for an into-plane application. Rated flow and 10 % rated flow cover operational range. 3 5 15 Tests using free water The initial pressure differential across a new element at rated flow is an indication of media permeability. This needs to be tight enough to filter efficiently but not so tight as to cause excessive pump energy losses. Description 16 Bulk water challenge at rated flow Bulk water challenge at 10% of rated flow Intended to assess the efficiency of filter blocking/fuel flow shutdown within the operational range. 50 ppm saline water challenge Intended to demonstrate a at rated flow minimal level of water absorbing Saline bulk water challenge at performance of ‘dirty’ water. rated flow Mechanical integrity of element saturated with water The water saturated element tested up to 175 psi (12 bar) differential pressure must not disintegrate. 6 Test dust removal (filtration) Particulate filtration is tested. The component must not disintegrate mechanically as a result of particulate loading (up to 175 psi (12 bar)) differential pressure. 7 Tests using test dusts 4 Mechanical integrity of element blocked with test dust Performance after a freeze/ thaw cycle Intended to confirm that any water in the element does not cause damage to the filter integrity when it freezes and thaws. 9 Full element immersion in water Intended to confirm that gel formation, which exerts a mechanical expansion force on the element, is not detrimental to integrity. 10 Other tests 8 Partial element immersion in water 11 Compatibility Considerations covered earlier in this chapter apply 17 Element end-to-end electrical resistance Introduced to ensure that electrostatic charges on elements are dissipated during operation. Table 9: EI 1583 Mandatory filter monitor full scale-test protocols Qualification Test Number Description Comments 13 Full scale 50 ppm water removal 14 Full scale water slug response Minimum flow rate of vessel is 1 136 l/min (300 gpm). Intended to confirm that performance of a full set of elements in a vessel is suitable. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 6 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 39 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Microfilters (EI 1590) Although microfilters are tested at a specified flow rate (to enable comparison between products), they can be used at any other flow rate as long as maximum differential pressure is not exceeded. The role of a microfilter is the removal of particulate matter. Its design therefore covers two parameters: high particulate capacity and particle size rating. The qualification of a microfilter requires six single-element tests, with no full-scale testing. The mandatory single-element tests are conducted on 150 mm (6 in.) nominal diameter elements with out-to-in flow format only, and are summarised in Table 10. The protocols require testing at a minimum flow rate of 10 l/sec/m of effective media length (equivalent to 6 l/min/cm or approximately 4 gpm/in.). Table 10: EI 1590 mandatory microfilter single-element test protocols Qualification Test Number 1 Test to confirm limited filter material migration and initial differential pressure across element. 2 Filter rating at 10 l/sec/m of effective media length 3 The test particulate used in the qualification testing of microfilters: Test For 5,0 μm rated elements: A-1 (ultrafine) silica Intended to ensure integrity of element when exposed to fuel flow and pressure, (and effluent fuel quality). These are the tests where the manufacturer proves the Filter rating at 5 l/sec/m of effective filtration rating at two flow rates. Test particulate is added at a media length concentration of 50 mg/l until a differential pressure of 22 psi (1,5 bar) across the element is achieved. (No test duration is specified). 4 Water resistance Many media that can be used for filtration are incompatible with water. Some cellulosic media in particular are very unstable and so this test is included, not to test for water removal but for media stability in the presence of water. The component must not disintegrate. 5 Compatibility Considerations covered earlier in this chapter apply. 6 Structural This test establishes a reasonable level of structural strength to assure the user that the component will not disintegrate under high differential pressures and subsequently recontaminate the system. For 1,0 μm rated elements: R9998 For 2,0 and 3,0 μm rated elements: 90:10 ratio of A-1 (ultrafine) silica and R9998 Comments Since the life of such components is very variable according to the variations in operating conditions (flow, level of particulate, type and size distribution of particulate) no contaminant holding capacities are specified. However, the minimum performance limits that are required are: Minimum performance criteria specified in EI 1590 for microfilters The effluent fuel downstream of the microfilter element shall contain less than 0,15 mg/l particles greater in size than the stated filter rating. Test dust transmissions shall be measured by the use of membranes according to the specific element rating as follows: 1,0 µm rated element 2,0 µm rated element 3,0 µm rated element 5,0 µm rated element 0,8 µm membranes 2,0 µm membranes 3,0 µm membranes 5,0 µm membranes Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file6is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 40 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Laboratory testing requirements Dirt defence filters (EI 1599) The specification for this filter type was introduced to provide an alternative to filter monitors (EI 1583) but without the water interception capability provided by the water absorbent media that characterises that type of component. The eight single-element tests required are based on those from EI 1583 and EI 1590 as shown in Table 11. Table 11: EI 1599 dirt defence filter test protocols Qualification Test Number Test Comments 1 Test to confirm limited filter material migration and initial differential pressure across element. Intended to ensure integrity of element when exposed to fuel flow and pressure. A 0,45 µm membrane is used to assess the nature of any material that is shed by the component. 2 Test dust removal at rated flow 3 Test dust removal at 50 % of rated flow Conducted at two flow rates for a fuel contamination level of 10 mg/l. 4 Water resistance See EI 1590 Test No 4, above. 5 Mechanical integrity of element blocked with test dust. See EI 1583 Test 7, above. 6 Mechanical integrity of element exposed to water then blocked with test dust. Assures the mechanical stability of the component under extreme duress. 7 Compatibility See above for all components 8 Element end-to-end electrical resistance See EI 1583 Test 17, above These components are required to perform in a similar way to filter monitors (in response to particulate matter) and therefore have to meet the following minimum performance criteria: The solids holding capacity is measured as the time taken for an element to reach 22 psi (1,5 bar) pressure differential at full rated flow with an influent test particulate addition rate of 10 mg/l. • Blocking time for 50 mm (2 in.) nominal diameter elements is at least ten minutes. • Blocking time for 150 mm (6 in.) nominal diameter elements is at least 50 minutes. Minimum performance criteria specified in EI 1599 for dirt defence filters Effluent fuel samples shall not exceed: a) Total solids 0,26 mg/l (1,0 mg/gal.) average - 0,5 mg/l (1,9 mg/gal.) maximum b)Appearance - the effluent fuel shall be clear and bright c)Media migration - 10 fibres/l Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 6 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 41 Chapter 7 Filter/water separators (EI 1581) OR SIMILARITY FOR API/IP 1581 AVIATION JET FUEL FILTER/SEPARATORS ssel and the separator line or shallow arc rator stages. Systems vertical or horizontal ow occurs in systems of gravity on water asses the cases where d to, and 3) transverse (c) Engaged: Layouts intermediate between side-toside and concentric fall in these classes (Figure 3). Systems using this design may have either vertical or horizontalKey orientation. When for engaged flow concepts users occurs in vessels oriented horizontally, the effect of gravity on water dropout separates intoaredifferent • Filter/water separators designed to remove free water and particulate from fuel. classes the cases where flow is 1) aligned with, 2) • They are the basic units in aviation fuel cleanliness control and are mandated in many opposed to, and 3) transverse to the attraction of industry operations, particularly in airport fuel handling operations. gravity. • Note key recommendations below. characteristic of this filter/coalescer stage Example of side-by-side e. configuration from EI 1582 What are the choices of filter/water separator? (plan view, separators shaded) Filter/water separators are available to operate in a number of specific fuel formulations that represent different operational challenges (“categories”). Within those categories there are also options for the level of expected fuel cleanliness, these options being designated “types”. They may operate in either horizontal or vertical “orientation“ and finally the filter/coalescer and separator elements within a vessel can be arranged with either a ‘side-by-side’, or ‘endopposed’ “configuration” (described further in EI 1582). Each configuration requires separate qualification. Within the categories and types, element flow rates may differ according to the particular manufacturing source, and so operators should carefully check the performance details of these elements as given by the manufacturer. As with many other elements, they can have screw-based or open-ended mountings, and be of varying length up to 1 422 mm (56 in.). Whilst they are most commonly encountered as 150 mm (6 in.) nominal diameter Example 1of end-opposed 2 SIMILARITY SPECIFICATION elements, other diameters are available particularly in military applications. Filter/coalescer of element layout: Side-to-side configuration elements flow in an in-to-out flow format whilst separator elements flow out-to-in. (side view) Options What category? Considerations for selection Category C filter/water separators (C for Commercial aviation fuel) Are tested with a fuel containing an additive package simulating a severe jet A-1 and are used in most commercial fuel handling systems. Note12: Category M filter/water separators (M for Military aviation turbine The additive package fuels (JP8)). Are tested with fuel containing an additive package12 used in 3 includes static dissipator, military fuels. of element layout: Concentric metal deactivator, anti-oxidant, corrosion Category M100 filter/water separators (M100 for thermal stability inhibitor, fuel system enhanced military aviation fuels (JP8+100)). Figure 4and - End-opposed classes of element layout:4 Cylindrical separators icing inhibitor. Are tested with category M fuel that contains an additional dispersant additive used to enhance thermal stability. Side view. The open rectangles are coalescer elements. The filled rectangles are separator elements. 2.4.2 What type? End-opposed classes Type S Intended for use at filtration points where significant levels of free water and particulate matter in the fuel can be expected. Equivalent to the 2.6 MODEL TYPE of B Class in previous editions of EI 1581. performance a) Vertical systems having elements in the endopposed layout populate different classes (Figure 4) when the flow is 1) opposed to and 2) aligned with the attraction of gravity. 2 The filter/coalescer and separator elements shall be the Type S-LD same models in both candidate and qualified systems. Intended for use at all filtration points where significant levels of free Elements shall be identical with respect to construction water but minimal amounts and media but may vary in length and end-cap type of particulate matter (LD = low dirt) can be of element layout: Engaged in the fuel. Examples of suitable locations could be immediately (open-ended/threadedexpected base). b) Systems having a single, non-cylindrical-shaped The outside diameter elements afterofaseparator microfilter or atmay locations where acceptable particulate matter (or "basket") separatorelements (Figure 5)arepopulate lements. The separator shaded.a vary. levels can be achieved without filtration (e.g. out-of-storage). different classa than systems having cylindricalThe orientation length-to-outside-diameter ratio of the rawings depict single element layout (class) in vertical but different layouts separators. separator elements (each stack of separator elements e ofshaped the dynamics of water dropout. Type S-LW when stacked) in the candidate system shall not exceed Intended for use at filtration points where very low levels of free water that of the qualified system. (LW = low water) are encountered (e.g. into-plane). 2.7 only. MEAN FLOW RATE Issued under license4to Phillips 66 aviation customers NotLINEAR for further circulation. IMPORTANT: This file7is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 42 Chapter The mean linear flow rate of the filter/coalescer the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 elements of the candidate system shall not exceed that of the qualified system. Filter/water separators (EI 1581) Options A filter/water separator can have either a vertical or a horizontal orientation. Consequently, the elements used in these vessels also have to be “qualified” in whichever orientation they are to be used. What orientation? Screw-based or openended? Side-by-side configurations are the most widely used in both vertical and horizontal vessels. FWS sumps should be drained regularly to prevent coalesced water exceeding sump volume. FWSs cannot handle this situation because the water repellent separator element is still a permeable material and if there is a sufficient pressure of water against it (the sump level increases significantly), the water will migrate through. Water level indicators are available to notify the operator when the sump is full. If the operation encounters large amounts of water, as evidenced by the need for frequent sump draining, then level indicators should be fitted. Similarly, water level alarms may be fitted if the outlet of the FWS is directly into-plane. Note automatic drain valves may be fitted to periodically drain the sumps of water. Considerations for selection • For certain flow rates there may only be a qualification in one orientation. • Ease of access – it can be difficult for operators to replace long elements in horizontal vessels, or to clean long narrow vertical vessels (where access platforms are typically required). • Horizontal vessels may be the only practical option for mobile applications, or those with height restrictions, but require a larger footprint than vertical ones. • The sump of a horizontal vessel has a smaller water to fuel interface ratio, which may offer benefits such as greater control of separated water (automatic detection) thus alleviating potential microbial activity. Horizontal vessels may incorporate larger defined sumps to provide greater flexibility in managing higher free water challenges. • New vessels can be ordered to accommodate either option. • Existing vessels either dictate mounting type, or require modification. • Dependent on vessel mounting. • The filtration and water removal performance is not affected by either mounting option. What • configuration? • Vessel design dictates element configuration. Length of element (up to 1 422 mm (56 in.))? • The vessel configuration and flow rate requirements dictate the length of elements. • For ease of handling shorter elements may be preferred. A larger range of side-by-side models are qualified to EI 1581, providing greater commercial flexibility. What are the key points to consider in FWS application/use? Key points to consider in application/use of filter/ water separators • They coalesce fine water droplets into large drops that settle out. It is recommended that a minimum of daily draining of FWS sumps at system pressure is carried out. • Where fuel contains excessive particulate matter causing short life of filter/water separator components, a microfilter (see chapter 4) may be considered for installation upstream to extend life. • They are not tested for the removal of amounts of water greater than 3% of the rated flow of the vessel. Water level alarms should be used if larger amounts of water are likely to be encountered. • Since water freezes at 0 °C, operations at or below this temperature may require vessel sump heating. • The structural integrity of elements is compromised by large pressure differentials and they should not be operated above 15 psi differential pressure. Cont.... Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 7 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 43 Handbook on equipment used for the maintenance and delivery of clean aviation fuel FWSs coalesce fine water droplets into large drops that settle out of fuel. It is recommended that a minimum of daily draining of FWS sumps at system pressure is carried out. Key points to consider in application/use of filter/ water separators continued See also, EI Research Report Investigation into the effects of lubricity additives on the performance of filter/water separators In this context ‘single-use’ means the filter/coalescer is used until it reaches the end of its service life and is then disposed of. A user should conduct an appropriate risk assessment before specifying Type S or Type S-LW. Some general guidelines are: - Hydrant servicers intended for use with hydrant systems known to periodically be wet should use Type S to maximise water handling capability. - Mobile applications which have an independent system to detect water (e.g. water probe, optical sensor or appropriate procedure) may normally use Type SLW even when used on wet hydrant systems. - Refuellers operated such that free water content is well-controlled normally would be fitted with Type S-LW. • They should not be operated at greater than the vessel rated flow as this will impair water separation. • Operating a vessel at less than 30 % rated flow, coupled with extended periods of vessel inactivity, has been reported to increase the risk of establishing microbial activity (leopard spotting) due to free water not being released from filter/coalescer elements. • The water removal performance may be adversely affected by surfactants or additives in fuel, a condition known as “coalescer disarming” (see Annex G for more information). EI 1581 5th edition qualified FWS are more resistant to surfactants than FWS qualified to previous editions. • Elements from different manufacturers have different differential pressures. If these are used in the same vessel, initial fuel flow will follow the path of least resistance and therefore preferentially flow through the elements with the lowest differential pressure. This may result in some of the elements being over-rated. Only elements of the same model/manufacturer should be used in a single vessel at one time. • Filter/coalescer elements are designed for single-use only (cannot be regenerated) but some separator elements can be checked. • Allowing water to remain in vessels will promote microbiological colonisation and this can cause “disarming”. In low flow conditions water droplets may remain on filter/ coalescer elements. • The means of disposal of water drains should be carefully considered, particularly where FSII is being used. • Where the FWS is exposed to fuel containing FSII it is recommended that category M or M100 elements only are used. • Sumps should be drained of free water at least daily, or their capacity may be exceeded. • Although Type S-LW systems can be smaller and lighter than other FWS systems, rendering them easier to use in mobile applications, users should appreciate that it is not appropriate to use Type S-LW systems in all mobile applications. • Type S-LW systems are not intended for, and should not be used in, fixed applications. • Filter/coalescers and separator models are qualified as a system within a vessel. This means that filter/coalescers and separators (for use in a FWS) must be obtained from the same supplier. Note that separators can have a longer service life than filter/coalescers, and can be reused according to manufacturer’s recommendations. • Element change-out criteria/separator inspection criteria should comply with manufacturer’s recommendations, see also chapter 19. These typically include high filter membrane readings, hazy fuel in the sump, evidence of microbial growth in sump water (including sulfurous odour), sudden drop in differential pressure, high levels of free water indicated in the outflow by water detection devices, exceeds 15 psi corrected differential pressure. • Sumps containing hazy fuel could be an indication that the filter/coalescer is no longer functioning correctly. Further investigation, including repeated sump drains, should be undertaken. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file7is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 44 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Filter/water separators (EI 1581) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 7 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 45 Chapter 8 Similarity for filter/water separators (EI 1582) Key concepts for users Similarity applies only to filter/water separators and is a protocol for: 1. Qualifying a FWS to EI 1581 by using a calculation methodology (given in EI 1582) rather than laboratory testing. 2. Ensuring that a FWS, whether existing or new, remains qualified to EI 1581, when the model/type of elements used is changed. 3.Allowing manufacturers to supply a range of vessel sizes without the need to perform laboratory qualification tests on every one. What is similarity? • Similarity is the methodology developed to minimise the number of full-scale tests that would otherwise be required to qualify a large range of FWS sizes to EI 1581. This is desirable because the scale and complexity of full-scale testing places significant demands on testing resources. This is qualification by similarity. • The concept is that full-scale testing is not needed if a candidate filtration system can be shown to be sufficiently similar to a system already qualified (by full-scale testing) to support the expectation that full-scale testing would meet EI 1581 requirements. Such a system is said to be “qualified to EI 1581 by similarity”. Similarity sheets should be provided by manufacturers If a FWS user wishes to replace the elements in a vessel with those of another model/type it is recommended that a similarity sheet be provided by the new supplier that documents that the FWS remains qualified to EI 1581. This documentation should be requested by the user and retained on file for the service life of the elements. The similarity sheet should indicate that all of the operational parameters meet or exceed the requirements stated for the original elements installed in the vessel. Such parameters include flow velocities through the elements, how they are oriented, how they were qualified, inter-element spacings, etc. A similarity sheet and corresponding data plate, should also be issued with each new vessel, to document the qualification to EI 1581 by similarity. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file8is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 46 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Similarity for filter/water separators (EI 1582) Note for existing FWS rated above 9 500 lpm (2 500 gpm): Although similarity criteria are not to be used to qualify new vessels of a higher flow rate than the qualified vessel (by full- scale testing), existing vessels qualified to previous editions (1st –3rd) of API 1581 with flow rates greater than 9 500 lpm (2 500 gpm), but no more than 19 000 lpm (5 000 gpm), may be qualified by meeting similarity criteria with vessels full-scale tested at 9 500 lpm (2 500 gpm). Key points to consider in the application of similarity for FWS • Similarity criteria may only be used to qualify a FWS at a flow rate equal to or lower than the design which was qualified by full-scale testing. • The range of flow rates for which similarity is valid is 0 – 9 500 lpm (0 – 2 500 gpm). • Manufacturers are required to provide customers with similarity documentation (similarity sheet and vessel plate) for the use of their elements in any vessel, and for any new vessel. • If replacement elements are of the same model/type as those they are replacing, the former similarity sheet continues to apply. • If a candidate FWS does not meet the requirements of EI 1582 it cannot be represented as being qualified to EI 1581. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 8 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 47 Chapter 9 Filter monitors (EI 1583) Key concepts for users • The intended performance of a filter monitor system is to remove low levels of particulate matter and trace levels of free water from aviation fuel to levels acceptable for servicing modern aircraft. It is also intended that in service a filter monitor system will restrict the flow of fuel before its capacity for particulate matter and/or water removal is exhausted. • Filter monitor elements should not be considered fail-safe, and should only be regarded as one component in the comprehensive system to protect aviation fuel quality. • Note recommendations below. Introduction EI 1583 6th edition includes a new laboratory testing protocol to quantify any migration of trace super-absorbent polymer (SAP) downstream of filter monitor elements under laboratory qualification test conditions. During the 1980s and 1990s filter monitors became the preferred filtration option into-plane, because at the time they were regarded as being ‘fail-safe’ and able to stop water under conditions where filter/coalescers are disarmed. Given the degree of quality assurance required for equipment used into-plane, much research has been conducted into the performance of new unused filter monitor elements, and also those removed from service and tested under laboratory conditions. That which has been generated under contract to the EI, or made available by test houses, has been used in the development of EI 1583 6th edition. What are the choices of filter monitor? The types of filter monitors specified in EI 1583 6th edition are as defined in Table 12. Table 12: Types of filter monitors specified by EI 1583 6th edition Options Flow format Lengths Fitting Considerations for selection 50 mm (2 in.) Out-to-in Up to 762 mm (30 in.) “push-in” bayonet (o-ring seal) Flows up to 2,5 l/sec/m (1gpm/in.) of element length 150 mm (6 in.) Out-to-in Up to 1 422 mm (56 in.) screw-based or open-ended Flows up to10 l/sec/m (4 gpm/in.) of element length 150 mm (6 in.) In-to-out Up to 1 422 mm (56 in.) screw-based or open-ended Flows up to 10 l/sec/m (4 gpm/in.) of element length Filter monitors can be of vertical or horizontal orientation. NOTE: Any of the above categories of element can also be qualified as ‘High Salt’ (HS) if they meet the requirement of EI 1583 6th edition Qualification Tests 15 and 16 using synthetic seawater (ASTM D 1141) rather than 0,5% (m/m) NaCl which is mandatory for all categories. In such cases ‘/HS’ should be added to the category designation. The fifth edition of EI 1583 contained a greater number of element categories (outlined in Table 13 in EI 1550 1st edition) to provide manufacturers with greater flexibility in their manufacturing techniques and product development programmes to reduce the possibility of super-absorbent polymer (SAP) migrating from the elements. The number of categories was reduced for the 1583 6th edition after an investigation into the actual levels of SAP migration experienced in operation, and consultation with filter manufacturers. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file9is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 48 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Filter monitors (EI 1583) What are the new developments in EI 1583 6th edition? The development of EI 1583 6th edition followed two years of industry research into SAP migration from new elements under laboratory conditions. The most significant cause of trace SAP migration was found to be debris from the element manufacturing/production process. Filter manufacturers have implemented new production techniques to minimise this as far as practicable. Industry research included the development of a more robust technique for quantifying the level of SAP migration during qualification testing, which is included in EI 1583 6th edition (as part of Qualification Tests 1 and 10). In previous editions the migration levels were determined by sidestream sampling, but in the new method all fuel that passes through the element under test subsequently passes through one or two bag filters (depending on flow rate). The bags are removed after the test and the quantity of the captured SAP determined. Manufacturers are required to declare this value in their qualification test report. Until testing experience is generated it is not possible to specify a robust performance limit for the quantity of SAP measured during laboratory qualification testing, and establishing repeatability and reproducibility values for the procedure, within the required trace level range of SAP, is unlikely to be possible. The industry expectation is that no SAP shall occur downstream of an element during Qualification Tests 1 and 10, but because of the nature of the media, and the measurement technique used, this may not be achievable and some tolerance may be required. Users are therefore encouraged to review the SAP result from Qualification Tests 1 and 10 with their filter monitor suppliers. Airframe or engine OEMs have not specified an acceptable level of SAP in fuel. The other major addition in the new edition is the requirement for a structural test to confirm adequate adhesion of element end caps (applicable to 50 mm nominal diameter and 150 mm nominal diameter screw-based versions only). This has been included following reports of element manufacturing issues (see chapter 15, Table 16). Users are encouraged to consider requesting, and manufacturers to consider implementing, this test as a regular part of manufacturing quality control programmes. What are the key points to consider in the application/use of filter monitors? Key points to consider in the application/use of filter monitors • The intended performance of a filter monitor system is to remove low levels of particulate matter and trace levels of free water from aviation fuel to levels acceptable for servicing modern aircraft. It is also intended that in service a filter monitor system will restrict the flow of fuel before its capacity for particulate matter and/or water removal is exhausted. • Filter monitors are not suitable for applications that may experience continuous water in fuel. • The water removal performance of filter monitor elements that comply with the mandatory requirements of EI 1583 6th edition may become degraded in service to a level that is unacceptable, (see Annex H). Therefore filter monitor elements should not be considered fail-safe, and should only be regarded as one component in a comprehensive system to protect aviation fuel quality. cont... Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 9 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 49 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Key points to consider in the application/use of filter monitors (continued) SAP is non-Newtonian in nature and so under high shear it “thickens” – just as custard does. Non-drip paints are the opposite – if you shake a can of nondrip paint it becomes more fluid. For water absorbent chemicals, shaking them makes them more rigid and it is this rigid resistance to flow that is utilised to block the passage of water through the elements. • The use of filter monitors that meet the requirements of EI 1583 6th edition alone cannot provide assurance that SAP migration from filter monitor elements will not occur. • If filter monitors qualified to EI 1583 6th edition become available and appropriate field evaluation confirms they are suitable for the intended application, (see chapter 5), a programme should be implemented to replace filter monitors qualified to earlier editions of EI 1583. • Elements should be changed out in accordance with manufacturers’ recommendations. Typically these include 12 months’ service life, or a stated differential pressure, whichever is sooner. • In the event of a sudden filter blockage, it is possible that fuel containing unacceptable levels of free water has passed downstream of the vessel. Procedures should be in place to investigate the cause, and if the filter monitor is in an into-plane application, agree an appropriate course of action with the customer. (Note this will depend on factors such as length of delivery hose.) • If short filter life is encountered (i.e. less than 12 months), the fuel handling system should be checked for cleanliness and suitable maintenance carried out. • Filter monitor integrity is tested to 175 psi (12 bar) differential pressure and is designed to withstand system pressure surges. • Filter monitors can be used as a third stage in filter/water separators downstream of the separator. • Filter monitors are typically used in into-plane applications, rather than further upstream in the aviation fuel handling system. • Filter monitor vessel sumps should be drained regularly of free water when the vessel is in use/under pressure, to ensure that water bottoms do not accumulate to a level that could compromise performance. Allowing water to remain in vessels will also promote microbiological growth. Simple routine draining when the vessel is not under pressure would result in monitor elements becoming exposed to air and the media drying out. • Filter monitors have a greater resistance to the adverse effects of surfactants than FWS. • Filter monitors should never be used in fuels containing FSII (see following text). Any FSII injection systems should be located downstream of filter monitors. • A filter monitor should be operated as closely as possible to its rated flow. Element and vessel sizing therefore needs to be carefully considered for each application. • Operating a filter monitor at a flow rate considerably lower than its rated flow (see manufacturers’ recommendations) is not advisable as this will reduce the ability of the elements to stop free water, especially slugs (consider down-rating the vessel by inserting blank elements. These can be supplied by filter monitor manufacturers so that the deck or base plate is blocked off and the interlock system of the vessel lid accommodated). • Elements from different manufacturers have different differential pressures. If these are used in the same vessel, initial fuel flow will follow the path of least resistance and therefore preferentially flow through the elements with the lowest differential pressure. This may result in some of the elements being over-rated. Only elements of the same model/manufacturer should therefore be used in a single vessel at one time. • Electrostatic discharges may occur in a vessel if it contains unbonded charge collectors (noted by sharp “clicking” noises during flow, and visible damage to elements removed from the vessel, see Figure 25). Such damage can reduce water removal performance and lead to potentially incendiary discharges. In such cases check the vessel for unbonded charge collectors (see Annex L). • Elements are designed for single-use only (cannot be regenerated). • After installation filter monitor elements should always be immersed in fuel. During maintenance operations elements should not be allowed to dry out. • Operators of 150 mm (6 in.) diameter elements should ensure that the direction of fuel flow through the element is correct. • After new elements have been installed it is recommended that the vessel be flushed with fuel of intended use for a minimum of three minutes at the maximum achievable flow, prior to the vessel going into service. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file9is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 50 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Filter monitors (EI 1583) EI 1583 does not include qualification testing for military fuels (that contain FSII). Research has shown that FSII in fuel (most commonly diethylene glycol monomethyl ether (DiEGME)) interferes with proper water absorption by the SAP, significantly reducing the water removal performance of filter monitors in fuels containing this additive. This has been a warning included in 1583 since its 3rd edition (2000). Further details are included in EI Research Reports Aviation fuel handling: The performance of filter monitors in fuel containing FSII and Investigation into the water holding performance of aviation filter monitors with absorbent-type elements, intended for military applications (available from the EI library). FSII can also cause the migration of SAP. The US Air Force reported extensively on the appearance of a light-coloured, gelatinous material present in vessel drains and coating elements. Analysis showed it to be mainly FSII with some water and varying amounts of SAP. The US Air Force and the US Navy have now discontinued the use of filter monitors in their systems. Research commissioned by the IP in 2001 identified that electrostatic charge could accumulate on two inch diameter filter monitor elements, causing possible incendiary discharges. Element end-to-end resistance requirements were subsequently included in API/EI 1583 4th edition, that resulted in manufacturers producing elements with conductive end caps. For further information see EI Research Reports: Electrostatic discharges in two-inch fuel filter monitors and Electrostatic discharges in two-inch aviation fuel filter monitors. Phase 2: Properties needed to control discharges. Figure 25: Examples of electrostatic damage to monitor elements Note: The damage may be subtle dark stains on the outer media wrap or more dramatic tears in media layers accompanied by burn marks. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance withChapter 9 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 51 Chapter 10 Microfilters (EI 1590) Key concepts for users • Microfilters are not designed to remove free water from fuel and should not be considered for that function. • Most frequently used to remove particulate matter thereby protecting downstream filter components. • Note recommendations below. What are the choices of microfilter? Unlike other filter components, microfilters qualified to EI 1590 are only 150 mm (6 in.) nominal diameter elements with out-to-in flow format. Microfilters are supplied as one of four micron ratings (defined in EI 1590 as 1,0 µm, 2,0 µm, 3,0 µm or 5,0 µm). They can have screw-based or open-ended mountings, and vary in length up to 1 422 mm (56 in.). Users should be aware that microfilters qualified to EI 1590 will only be marketed by suppliers as one of these four micron ratings. If another rating is encountered, that filter should not be regarded as being qualified to EI 1590. Options What micron rating? 1,0 µm, 2,0 µm, 3,0 µm, 5,0 µm Screw-based or open-ended? Length of element (up to 1 422 mm (56 in.))? Considerations for selection • The micron rating does not affect the physical dimensions of the element. • Since element life in a given application is a function of both particulate loading and flow rate, it is recommended that purchasers consult with their microfilter suppliers to establish the optimum flow rate or vessel size for their applications. It should be noted that operational experience is likely to be required to determine the optimum micron rating for the microfilter system. The rating should be sufficient to protect downstream filter components from developing increased differential pressure. • New vessels can be ordered to accommodate either option. • Existing vessels either dictate mounting type, or require modification. • Dependent on vessel mounting. • The filtration performance is not affected by either mounting option. • Determined by the element mounting arrangement within existing vessels. • Required surface area of filter for new vessels. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file10 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 52 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Microfilters (EI 1590) Other selection choices? There is a relationship between the surface area of the microfilter (that is exposed to fuel flow) and its capacity to hold particulate matter (at a given flow rate and particulate loading). The relationship is not linear, so there are benefits in maximising the surface area of the microfilter (i.e. doubling the surface area gives more than double the particulate holding capacity). Consideration can be given to the operational benefits of: • selecting elements that have the greatest number of pleats, assuming that their operational surface area is always exposed to fuel (pleats are not compressed), or • the use of elements of a multi-layered construction to improve filtration efficiency, or • installing a greater number of elements in a vessel. What are the key points to consider in microfilter application/use? Key points to consider in application/use of microfilters ‘Single-use’ means the microfilter elements are used until they reach the end of their service life and are then disposed of. • Microfilters are not designed to remove free water from fuel and should not be considered for that function. • Where fuel may contain excessive particulate matter causing short life of filter components in the aviation fuel handling system, microfilters can be used for the ‘protection’ of other filter components. • Microfilter integrity is compromised by large pressure differentials. They should not be operated above the manufacturer’s recommended maximum differential pressure. • Microfilter integrity can be compromised by prolonged exposure to water bottoms. • Microfilters are not adversely affected by surfactants or additives in fuel. • Not recommended for use in into-plane applications. • Microfilter elements are designed for single-use only (cannot be regenerated). • Element change out criteria should comply with manufacturer’s recommendations. • Elements from different manufacturers have different differential pressures. If these are used in the same vessel, initial fuel flow will follow the path of least resistance and therefore preferentially flow through the elements with the lowest differential pressure. This may result in some of the elements being over-rated. Only elements of the same model/manufacturer should be used in a single vessel at one time. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 10 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 53 Chapter 11 Dirt defence filters (EI 1599) Key concepts for users • Dirt defence filters are designed to remove particulate matter from fuel to a level suitable for refuelling aircraft. They are not designed to remove free water. • It is critical that if used into-plane, they are used in conjunction with an electronic sensor (EI 1598) or other means of detecting free water. • Note recommendations below. What are the choices of dirt defence filters? As EI 1599 was only published in 2007, the options for commercially available dirt defence filters were limited at the time of publication of EI 1550. This will be the case until manufacturers have progressed development and qualification. The options given in the following table represent the scope of the document and the user is advised to contact manufacturers for further information on availability. At the time of publication dirt defence filters were not recognised by any of the industry operational guidance documents. Options What category? Dirt defence filters give users another element option for installation in existing filter monitor vessels, but see also key considerations. Screw-based, openended or o-ring seal? Length of element? What orientation? Considerations for selection • 50 mm (2 in.) nominal diameter, for installation in existing or new 50 mm (2 in.) compatible filter monitor vessels used mainly on refuelling equipment. • 150 mm (6 in.) nominal diameter, for installation in existing or new 150 mm (6 in.) compatible filter monitor vessels. • New vessels can be ordered to cater for any option. • Existing vessels either dictate mounting type, or require modification. • Dependent on vessel mounting. • The filtration performance is not affected by either mounting option. • 50 mm (2 in.) nominal diameter elements are available in 125 mm (5 in.) length increments from 125 mm (5 in.) minimum nominal length to 762 mm (30 in.) maximum nominal length. • 150 mm (6 in.) nominal diameter, determined by the element mounting arrangement within the vessel. • Horizontal or vertical. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file11 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 54 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Dirt defence filters (EI 1599) What are the key considerations in the application/use of dirt defence filters? Key considerations in the application/use of dirt defence filters In this context ‘single-use’ means the dirt defence filter is used until it reaches the end of its service life and is then disposed of. • Dirt defence filters are not designed to remove free water from fuel and it is critical that they are used only in conjunction with an electronic sensor (EI 1598) or other means of detecting free water. • 50 mm (2 in.) nominal diameter elements operate at flow rates up to and including 2,5 l/sec/m (1 gpm/in.) of element length. • 150 mm (6 in.) nominal diameter elements operate at flow rates up to and including 10 l/sec/m (4 gpm/in.) of element length. • If short life is encountered (i.e. less than 12 months), the fuel handling system should be checked for cleanliness and suitable maintenance carried out. • Their structural integrity is tested to 175 psi (12 bar) differential to ensure that they can withstand system pressure surges. • They are not adversely affected by surfactants or additives in fuel. • They are designed for single-use only (cannot be regenerated). • Element change-out criteria should be as per manufacturer’s recommendations. These may include high filter membrane readings, high differential pressure and sudden drop in differential pressure. • Elements from different manufacturers have different differential pressures. If these are used in the same vessel, initial fuel flow will follow the path of least resistance and therefore preferentially flow through the elements with the lowest differential pressure. This may result in some of the elements being over-rated. Only elements of the same model/manufacturer should be used in a single vessel at one time. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 11 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 55 Chapter 12 Three-stage filtration (vessels) What is three-stage filtration? It is possible for filter/coalescer, separator and filter monitor elements to be combined in a single vessel. In such vessels the filter monitor elements are located downstream of separators (positioned inside them) see Figure 26 below, and are referred to as the ‘third-stage’. The concept is that if the FWS becomes disarmed, and allows water to pass, the filter monitors provide the required protection, and subsequent shutdown of flow. In Figure 26 fuel flows from inside to outside of the filter/coalescer elements, and outside to inside the separator and filter monitor elements. Filter monitor elements Filter/coalescer elements Separator elements Fuel outlet Fuel inlet Figure 26: Schematic of three-stage filtration Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file12 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 56 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Three-stage filtration (vessels) What are the key considerations in the application/use of three-stage filtration? Key considerations in the application/use of threestage filtration Three-stage systems are not widely used in commercial aviation fuel handling systems. • It should be noted that in such vessels the filter/coalescer and separator elements should meet the requirements of EI 1581 and the filter monitor elements should meet the requirements of EI 1583. • The combination of the elements in the three-stage vessel should be qualified to EI 1581 by meeting full-scale testing requirements (described in 4.4.5.6 of the 5th edition.) • The flow rate through the vessel should not exceed the flow rate used during qualification testing (in accordance with EI 1581 or EI 1583) of any of the elements. Manufacturer’s recommendations should be followed. • There may be confusion when continuously monitoring the differential pressure across the vessel, as the stage contributing to the change in differential pressure is not identified (all elements in vessel would require replacing), unless there are separate differential pressure readings across each of the stages. • Vessel designs to accommodate the third stage are typically quite complex, meaning non-standard lengths of elements may be required. • The media migration barrier used in the filter monitor element is protected from exposure to fine particulate matter as it is removed by the filter/coalescer. • Additional protection may be offered by the filter monitor elements in the event of the filter/coalescers becoming disarmed, or if a water slug occurs that is sufficient to overflow the separators. • Also see ‘Key considerations’ for both FWSs and filter monitors. Can a three-stage system be modified to a FWS? It is possible to modify the three-stage system to be only a FWS by the removal of the filter monitor elements. However, the FWS will then need to be requalified to confirm it meets the requirements of EI 1581, by using similarity (EI 1582). Achieving requalification may require the use of different separator elements. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 12 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 57 Chapter 13 Filter vessels (EI 1596) What is EI 1596? EI 1596 1st edition was published before the publication of the new laboratory test specification for dirt defence filters, EI 1599. It is recommended that the requirements for dirt defence filter vessels are based on those for filter monitors, in discussion with the manufacturer. Since the first edition of the specification for filter/water separators (API 1581) in 1973, the general design specifications for the pressure vessel used to house filter elements, have been an integral part of the publication. The same applied when the former Institute of Petroleum (EI) published the first edition of the specification for filter monitors (1987) and microfilters (1999). With much commonality between vessel design requirements, EI recently collated the vessel design requirements from the filter testing publications and combined them into EI 1596 Design and construction of aviation fuel filter vessels (1st edition, 2006). That publication provides the industry with minimum mechanical specifications for the design and construction of the three main types of aviation fuel filter vessels: filter/water separators, filter monitors and microfilter vessels. It is recommended that any new filter vessels used in aviation fuel handling systems be designed and constructed in accordance with the minimum requirements of EI 1596. (Note 1596 does not cover vessels intended to be used as clay treaters.) What vessel design parameters are considered ‘General’? EI 1596 specifies the parameters shown in Table 14 that are considered to be applicable to any type of vessel intended to house filters (that meet the requirements of EI 1581, EI 1583, EI 1590 or EI 1599). Table 14: Design requirements applicable to all types of filter vessel Main construction Connections Internal Design pressures Piping connections Access to elements Design codes Ports and connections Element supports Exterior Branch and port markings Data plates Hydrostatic test pressure Pressure ports Exterior paints Materials of constructon Vent and pressure relief ports Standard accessories Electrical continuity Drain and sample ports Drawings Clean-out connections Optional accessories Work platforms Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file13 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 58 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Filter vessels (EI 1596) Figure 27: Illustration of a filter vessel in vertical orientation What vessel design parameters are specific to the type of filter? Table 15 shows the parameters that are included in EI 1596 that are specific to vessels intended for use with one of three types of filter element. Table 15: Vessel design requirements specific to filter elements to be housed Filter/water separators Filter monitors Design pressure Hydrostatic test pressure Microfilters Element spacing Element mounting Element sealing Interlock systems Head lift retaining device Data plate Standard accessories Optional accessories Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 13 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 59 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Can vessels designed to house one type of filter be converted to house a different type? For certain applications, yes they can. Annexes I and J provide recommendations on the types of conversions that are technically possible. It is recommended that when deciding whether to convert a vessel from one application to another, the user obtains suitable technical information from one or more filter manufacturers, to ensure that the conversion will be technically successful and commercially viable. What about my ‘old’ vessels? It is recommended that the use of non-sloped flat-bottom filter/water separators (which have not been compliant with the requirements of 1581 since the publication of the 3rd edition in 1989) be discontinued in aviation fuel handling systems. The accumulation of water on non-sloped flat level surfaces in such vessels supports the growth of microbes resulting in microbiological contamination problems. Where a vessel that was designed and constructed to a specification pre-dating EI 1581, EI 1583, EI 1590 or EI 1596, is considered for continued use (with filter elements that do meet current editions of EI 1581, EI 1583 or EI 1590), the purchaser should be satisfied that the vessel is suitable for its intended service. The following items may assist in this assessment: • Is the vessel fit-for-purpose? • Does the vessel meet current applicable design codes? • Do vessel/element configurations meet the element manufacturers’ recommendations? • For filter/water separators, does the vessel element orientation and flow rate meet (by test or similarity) the requirements of the latest edition of EI 1581? • Does the vessel require the addition of an internal lining to prevent corrosion? • When converting to filter monitor use, does the deck plate require strengthening or protection by the addition of a pressure limiting device? • Is additional care required to ensure that elements are installed correctly? Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file13 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 60 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Filter vessels (EI 1596) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 13 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 61 Chapter 14 Electronic sensors (EI 1598) Key concepts for users • There is little experience within the aviation fuel handling industry of the use of electronic sensors for the detection of particulate matter and/or free water. • A wide range of technology may be able to meet operational needs, but work to confirm this remains in its infancy. • EI 1598 has been recently published, to provide a description of the general into-plane fuelling operating parameters, and limited performance requirements. It does not contain qualification tests, so electronic sensors cannot be ‘qualified to EI 1598’. It is intended to assist sensor developers in their understanding of the needs of the aviation fuel handling industry. • Sensors should only be used in conjunction with appropriate filtration equipment. What are the choices of electronic sensors? • All electronic sensor designs capable of detecting free water and/or particulate matter are within the scope of EI 1598. • Users should only consider the application of electronic sensors that are demonstrated by the supplier as being in compliance with the minimum safety and performance requirements of EI 1598, see box below. • They may be simple detection devices, or ones that are more complex, and capable of providing more information to users. • Examples of technology that may be able to meet the requirements of EI 1598, that the EI is currently aware of, include devices that utilise light-obscuration, light-scattering, particle sizing/counting, capacitance and infra-red. • EI 1598 is primarily intended to apply to electronic sensors for use on vehicles (hydrant servicers, carts or refuellers). Minimum performance requirements specified in EI 1598 for electronic sensors • Equipment designed to detect free water only, or both particulate matter and free water contaminants simultaneously, shall be capable of consistently detecting 25 ppmv, and more, of free water (this includes bulk water). • Equipment designed to detect particulate matter only, and/or particulate matter and free water contamination, shall be capable of consistently detecting suspended particulates at 0,20 mg/l and above. • Equipment designed to detect both particulate matter and free water simultaneously shall be capable of consistently detecting 25 ppmv, and more, of free water (this includes bulk water) and consistently detecting particulate matter at 0,20 mg/l and above. • Equipment that measures particle counts shall, as a minimum, be capable of detecting as low as ISO code 10 at 4 μm (c), 14 μm (c) and 30 μm (c). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file14 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 62 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Electronic sensors (EI 1598) What are the key considerations in the application/use of electronic sensors? • The successful application of electronic sensors will require significant experience with the device by the operator. The effective handling of sensor outputs/data is considered to be key to their successful application. • Operational field experience is required before it can be determined whether a particular sensor is fit-for-purpose. • Sensors may be sensitive to environmental parameters (e.g. temperature). • Air entrainment or gas bubbles may have an effect on the readings from some types of sensors. • Positioning of the point of installation to ensure representative measurement of fuel. • What are the desirable output displays and units? • Sensors should only be used in conjunction with fuel filtration components. Ideally they will confirm that filtration continues to be effective, or that maintenance is needed. • Sensors should be calibrated in the type of fuel in which they will be used. • Equipment must be certified safe to use in a hazardous area. • Ease of installation, access, power requirements. • What are the maintenance requirements? Does the sensor have a self-checking function? • Electronic sensors are intended for continuous use. • If the entire fuel flow is not monitored then sampling must provide an accurate representation of the total fuel flow. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 14 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 63 Chapter 15 Quality assurance of filter element and vessel manufacture Production processes and product quality assurance • Manufacturing methods/techniques for filter elements are not specified by EI laboratory qualification specifications. However, manufacturers should be able to demonstrate compliance with an appropriate quality assurance and management system. As a minimum this should be ISO 9001 Quality management systems - requirements or equivalent. It is recommended that it includes regular testing of elements taken from the production line, using qualification tests. Documented evidence should be available that confirms this is being undertaken. • Production runs of elements should be assigned a unique batch number for traceability. • It is the responsibility of the manufacturer to ensure that all production filters have a performance that is consistent with the model that was qualified. • Once a filter model is qualified no design, materials or construction changes are to be made by the manufacturer for production elements. Should such changes be required, requalification of the filter model may be necessary. Minimum recommendations for the requalification of previously qualified filter monitor elements are included in EI 1583 5th edition and for dirt defence filters in EI 1599. It is the intention to include similar recommendations for FWS and microfilters when EI 1581 and EI 1590 are revised in future. • Manufacturing techniques should ensure that filters do not contaminate or adversely affect aviation fuel when in service. • Although certain aspects of vessel construction are covered by EI 1596, that publication does not include details of manufacturing methods or techniques. • Manufacturing processes and facilities should follow good health, safety and environmental procedures, and production engineering practices. Manufacturing methods/techniques for filter elements are not specified by EI laboratory qualification specifications. What types of element manufacturing problems have been experienced? Manufacturing faults may be apparent prior to element installation. In other cases, faults are only identified during operation, or element removal. Some examples of operational experience of filter manufacturing faults are outlined in Table 16. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file15 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 64 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Quality assurance of filter element and vessel manufacture Table 16: Filter element manufacturing faults Fault Consequence End cap coming off due to inadequate adhesive bonding Will allow fuel to bypass the element media. End caps not level Causes difficulty in installation and may permit fuel to bypass media when filter is installed to required torque. Burst element casings Allows fuel to bypass media and can also contaminate the fuel with media. (Note: this may also be caused by high surge pressures during operation, and hence is not necessarily a manufacturing fault.) Media seam weld defects May cause fuel to bypass media. Diagnosis is difficult without dissecting filter. Media migration Can occur if media are not compatible with operational requirements. (Note: this may be caused if filter is used outside of manufacturer’s recommendations/operational design envelope.) What should I do if element faults are experienced? • In the event of element faults occurring (either identified prior to installation, or during operation), the manufacturer should be immediately alerted. Manufacturers then have a duty of care to their customers to clearly communicate known manufacturing defects that may have affected a particular batch of elements (which can be traced via their unique batch number). • In such circumstances the severity of the failure should be assessed. In certain cases it may be necessary for a manufacturer to recall the entire batch of elements. • Where element faults are identified during operation, it should be confirmed that the failure was not caused by the filters being operated outside of manufacturer’s recommendations. • If operators are not satisfied with the quality of filters being replaced they should make direct representations to the manufacturer concerned. What type of vessel manufacturing problems have been experienced? It is important that the interior vessel coating has been appropriately applied. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 15 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 65 Chapter 16 Application of components in aviation fuel handling systems Readers should also note the recommendations for low point sampling included in Annex K. JIG 1 Guidelines for aviation fuel quality control and operating procedures for joint into-plane fuelling services, JIG 2 Guidelines for aviation fuel quality control and operating procedures for joint airport depots, JIG 3 Guidelines for aviation fuel quality control and operating procedures for jointly operated supply and distribution facilities. JIG requirements are typically applied at JIG member company jointventure locations, typically outside of the US. ATA 103 and API 1595 recommendations are intended for, and typically implemented, in the US only. The requirements of any of the publications may be mandated anywhere worldwide by the fuel customer (airline), or applied anywhere at the discretion of the operator. For the handling of aviation gasoline API 1595 recommends the use of a FWS, filter monitor or 5 micron microfilter into the pre-airfield storage/terminal and a FWS, filter monitor or 5 micron microfilter at the outlet from the pre-airfield storage/terminal. JIG recommends the use of a 5 micron microfilter both into and out of airport storage, and a 5 micron microfilter or a filter monitor intoplane. The previous chapters in this publication have introduced a number of components that may be used either on their own or in combination to maintain fuel cleanliness in an aviation fuel handling system. It is important that careful consideration be given to the selection of components and where they are used in the aviation fuel handling system. The following information is provided to assist with identifying possible options. Minimum requirements for filter application for compliance with industry guidance Minimum requirements/recommendations for the application of types of filters at five locations in the aviation fuel handling system (into pre-airfield storage/terminal; out of pre-airfield storage/terminal; into airport storage; out of airport storage and into-plane) are given in JIG 1, 2, 3, ATA 103 and API 1595. The requirements of those publications are summarised below and in Figure 28. Minimum requirements for filter application for compliance with industry guidance for jet fuel handling Into pre-airfield storage/terminal: • FWS (meets API 1595 recommendation for truck transport/rail receipt points, see also discussion under ‘Key points’ to note of recommendations/good practice later in this chapter, page 72) Outlet from pre-airfield storage/terminal: • FWS (meets API 1595 recommendation) • Filters of at least 200 mesh linear inch (60 microns) (meets JIG requirement for fuel movement to vehicle loading points or internally lined delivery pipelines) • FWS or microfilter (meets JIG recommendation for fuel movement directly to airport service tanks) Into and out of airport storage: • FWS or filter monitor, with upstream microfilter as optional (meets both ATA 103 and JIG requirements) Into-plane (on refueller, hydrant servicer or cart): • FWS or filter monitor (meets both ATA 103 and JIG requirements) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file16 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 66 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Application of components in aviation fuel handling systems API 1595 only Filter/Water Separator Pre-airfield Storage Terminal API 1595 only Filter/Water Separator From Refinery JIG only 60 micron mesh ATA 103 or JIG Multi-product Pipeline Filter/Water Separator Dedicated Pipeline Airport Fuel Depot Tanker/Truck ATA 103 or JIG Filter Monitor Filter/Water Separator Tank/Car Filter Monitor Barge Ship ATA 103 or JIG Refueller Filter/Water Separator Aircraft Hydrant Servicer Filter Monitor Hydrant Cart Figure 28: Schematic of minimum requirements for filter application Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 16 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 67 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Options for application of components At locations where JIG or ATA 103 recommendations/requirements are not being applied/ followed, it is possible to adopt a wide range of combinations of filter components at each of the five filtration locations within the aviation fuel handling system. Figures 29 and 30 provide examples of the component types that could be applied, and give key factors that should be considered when deciding on the suitability of the components for each of the locations. The key considerations in the application/use of the components outlined in the previous chapters should also be consulted as part of the decision making process. Any decisions will be dependent on the operating parameters and environment prevalent at the specific location. Figure 29 highlights the filter components that could be applied into-plane (on vehicles). Figure 30 highlights the filter components (including those in combination) that could be applied (in separate vessels) at any one of four locations (into and out of pre-airfield/terminal storage, and into or out of airport storage). The factors for consideration given are those which apply to the combination of the two types of filter, rather than the filters separately. Key considerations for component combinations • Utilising different filter technologies at different stages in the fuel handling system may help to mitigate the risk of one type of filter component being rendered ineffective by an unusual operating parameter. • It is important to have a full appreciation of the operating environment (in terms of particulate matter and/or free water contamination) and the most suitable filtration component for that application. • The level of protection required at each of the five stages in the aviation fuel handling system. • Where fuel may contain excessive particulate contamination causing short filter/ coalescer life, it is recommended to “protect” the FWS with a microfilter of an appropriate micron rating, qualified to EI 1590. • Generally it should not be necessary to “protect” the FWS with a microfilter system in the out of storage location, because particulate matter should be removed before the fuel is received into airport storage and the storage should be managed to avoid contamination. It is, however, possible that local conditions may result in high levels of airborne particulate matter, which may enter the fuel handling system through tank vents. In such cases it is recommended to protect the FWS with a microfilter. • Hydrant systems operate at high pressure, easily high enough to burst a heavily loaded (blocked) filter/coalescer. Filter monitor elements are designed and tested to tolerate much higher differential pressure. • Filter monitors should not be used in fuel containing FSII additive. • Filter components should be sized for the flow rate required. In situations where combinations are used and flow rates differ, no component should be subjected to flow rates above its rated flow. • Future changes in vessel service should be considered prior to procurement of new vessels (i.e. FWS to filter monitor). • The ease of installation and maintenance. • The efficiencies and most effective means of optimising the fuel handling system (consideration of lifetime of different components). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file16 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 68 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Application of components in aviation fuel handling systems Filter location into-plane (refueller, hydrant servicer or cart) Filter component that could be applied Filter monitor (EI 1583) FWS (EI 1581) Dirt defence filter (EI 1599) Key decisions required by specifier Which diameter? - 50 mm (2 in.) - 150 mm (6 in.) Which category? -C -M - M100 Which diameter? - 50 mm (2 in.) - 150 mm (6 in.) For 150 mm (6 in.) which flow format? - in-to-out - out-to-in Which type? -S - S-LD - S-LW + water detection? To be used with electronic sensor (EI 1598)? To be used with electronic sensor (EI 1598)? Key factors to consider in selection of filter system, • see relevant chapters for • further information • • • • Tolerant to surfactants in fuel Intended to provide bulk water and low level water removal Should not be used in fuel that contains FSII May be subject to trace levels of SAP migration Water removal performance may degrade in service Use of electronic sensor may identify filter monitor malfunction • • • • • • • • Overcomes concerns with trace SAP migration into fuel Provides no bulk water removal function Coalescers vulnerable to disarming by surfactants leading to degradation in water removal performance Operational limitation of relatively large vessel size Diligent application of procedural checks required to prevent microbial growth in water sumps (see chapter 7) Category M or M100 only should be used in fuel containing FSII Type S-LW systems not suitable for all mobile applications Use of electronic sensor may identify FWS malfunction Only to be used with electronic sensor (EI 1598). Which type? • • • • • This option does not meet recommendations/ requirements of ATA 103 or JIG/IATA. Overcomes concerns with trace SAP migration into fuel Provides no water removal function Critical that it is only applied in conjunction with a water sensor Requires operational procedures to respond to sensor alarm condition Figure 29: All options for into-plane fuelling Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 16 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 69 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Filter location Into or out of-storage at either a pre-airfiled/ terminal, or at an airport F F Filter component that could be applied Filter monitor (EI 1583) Key decisions required by specifier Key factors to consider in selection of filter system • • • • • • • • • FWS (EI 1581) Which diameter? - 50 mm (2 in.) - 150 mm (6 in.) Which category? -C -M - M100 For 150 mm (6 in.) which flow format? - in-to-out - out-to-in Which type? -S - S-LD To be used with electronic sensor (EI 1598)? To be used with electronic sensor (EI 1598)? Tolerant to surfactants in fuel Intended to provide bulk water shutdown and low level water removal Should not be used in fuel that contains FSII May be subject to trace levels of SAP migration Water removal performance may degrade in service Requires large filtration surface area to have high capacity for particulate matter Use of electronic sensor may identify filter monitor malfunction or degradation Into storage location may suffer short service life if fuel contains high water loading Out of storage location may suffer short service life if tank draining procedures not diligently applied • • • • • • • Overcomes concerns with trace SAP migration into fuel from filter monitors Provides a combined particulate matter and low level water removal function Provides no bulk water removal function but sump water level detectors can alert operator Coalescers vulnerable to disarming by surfactants Operational limitation of relatively large vessel size Diligent application of procedural checks required to prevent microbial growth due to retained water Category M or M100 only should be used in fuel containing FSII Microfilter (EI 1590) Which micron rating? To be used with electronic sensor (EI 1598)? • This option does not meet recommendations/ requirements of ATA 103 or JIG/IATA. *Vulnerable if subjected to prolonged exposure to fuel with high free water levels • Overcomes concerns with trace SAP migration into fuel from filter monitors • Provides no water removal function Figure 30: All options for into pre-airfield/terminal storage, out of pre-airfield/ terminal storage, into-airport storage and out of airport storage Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file16 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 70 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Application of components in aviation fuel handling systems F F Combination of microfilter upstream of FWS Combination of FWS upstream of filter monitor Choices as for microfilters and FWS separately • • • Extends service life of FWS at locations with high particulate matter loading (into-storage). Usually unnecessary out of storage Provides greater capacity for particulate matter removal Sudden change in differential pressure of one vessel requires investigation of both Combination of microfilter upstream of filter monitor Choices as for FWS and filter monitors separately • • Provides additional protection in applications receiving fuel that may contain surfactants Sudden change in differential pressure of one vessel requires investigation of both Choices as for microfilters and filter monitors separately • • • Extends service life of filter monitor at locations with high particulate matter loading (intostorage). Usually unnecessary out of storage Provides greater capacity for particulate matter removal Sudden change in differential pressure of one vessel requires investigation of both Figure 30 (cont.): All options for into pre-airfield/terminal storage, out of pre-airfield/terminal storage, into-airport storage and out of airport storage Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 16 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 71 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Recommendations/good practice for application of components in aviation fuel handling systems Figure 31 shows an example of good practice in the application of filter components in the aviation fuel handling system. Despite the apparent complexity of filtration options available for each filtration location, typical fuel handling systems can be fairly straightforward. Key points to note • As noted in chapter 2, because of the challenges posed by the complex distribution system, a means of removing both particulate matter and free water is required. A FWS provides the most efficient and economical method of achieving this, and is the workhorse of the aviation fuel handling system. • The installation of appropriate filtration at pre-airfield storage receipt points should be considered if a site has a history of excessive particulate matter and/or water ingress or has a significant probability that receipts might have particulate matter and/or water content. Note the recommendation of API 1595 to install filtration at points receiving from truck/rail transport is intended to address the latter because it can be difficult to ensure trucks and rail cars are managed to aviation standards. • In applications where high particulate matter loading may occur, a FWS can be protected by the positioning of a microfilter upstream. • It is recommended that microfilters are not used in applications where there may be high levels of free water, such as may be experienced at marine receipt locations. • Although the application of clay treaters is not covered in this publication, it is recommended that microfilters are installed downstream of clay treaters to prevent carryover of clay into the fuel handling system. • Consideration should be given to protecting the clay treater by the positioning upstream of a filtration component (hay pack, microfilter, or FWS depending on operational parameters). • Filter monitors are not widely used outside of the supply system (at airports), as the challenge of water in the distribution system can be significant. FWSs allow for the continuous removal of low levels of free water, whereas filter monitors would regularly shut-down and require replacement. • Filter monitors into-plane are designed to shut down in the event of excessive particulate matter and/or free water contamination. Assurance of the performance of filter monitors may be provided by the application to vehicles of electronic sensors for the detection of particulate matter and free water. • Although not shown in Figure 31, it is possible to apply an electronic sensor downstream of any of the filtration locations to monitor fuel contamination levels and filter performance (noting that EI 1598 only applies specifically to mobile applications). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file16 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 72 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Application of components in aviation fuel handling systems Optional Filter/Water Separator Pre-airfield Storage Terminal Filter/Water Separator From Refinery Batching Tank Microfilter Clay Treater Optional Hay Pack Microfilter Filter/Water Separator &ILTER7ATER 3EPARATOR Optional Dedicated Pipeline Microfilter Airport Fuel Depot Multi-product Pipeline Tanker/Truck Filter/Water Separator Tank/Car Barge Ship Refueller Filter/Water Separator Aircraft 1598 Sensor Hydrant Servicer Hose end strainer Filter Monitor Hydrant Cart Figure 31: Schematic of recommendations/good practices for application of components in aviation fuel handling systems Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 16 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 73 Chapter 17 Operation of filter vessels - general health and safety considerations This chapter highlights key health and safety issues for the operation of filter vessels, it is not intended to be a detailed operations manual. Regional regulations should always be complied with. Lifting operations Lifting operations associated with the operation and maintenance of filter vessels will most commonly involve the raising and removal of the cover but may also involve the removal of other components. All lifting operations should be planned, supervised and carried out in a safe manner by trained and competent persons using approved and properly maintained equipment. The area underneath or potentially affected by the lift must be kept under control and clear of unnecessary persons or equipment. The minimum recommendations for lifting equipment are that it should be: • Sufficiently strong, stable and suitable for the proposed use. Similarly the load and anything attached (e.g. lifting / jacking points) should be suitable. • Positioned or installed to prevent the risk of injury. • Inspected and certified with a minimum frequency of 12 months. • Visibly marked with appropriate information regarding its safe use (e.g. safe working load). Control of work Due to the potential hazards that may exist, or be created during filter vessel maintenance and subsequent recommissioning, such tasks must be carried out in a safe and controlled manner. The control of work process should ensure that these tasks are: • Carried out by trained and competent staff. • Subject to a written method statement. • Risk assessed. • Subject to a relevant Permit-to-Work where required. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file17 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 74 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Operation of filter vessels - general health and safety considerations Safe isolation of plant Prior to the draining and opening of a filter vessel for maintenance, an appropriate means of isolation of the vessel must be provided to ensure that there can be no harmful release of product. This typically requires a minimum of two isolation points – upstream and downstream – and often more to cover additional pipework, instrument connections etc. The adequacy of isolation depends upon a number of factors such as the system pressure, flammability and toxicity of fuel and the period that isolation is required. Isolation can vary from simple single valve closure before and after the vessel, to the use of double valve or spades (for more extended periods, or if the filter is to be left open unattended), through to complete disconnection of the vessel from the system. Where appropriate, a lock-out tag-out (LOTO) system should be used to prevent inadvertent operation of pumps, valves etc. associated with the vessel undergoing maintenance. Confined space entry A confined space is one that is large enough for personnel to enter, has limited or restricted means of entry, and is not designed for normal or continuous occupancy. Some filter vessel maintenance tasks, such as internal cleaning or access to certain components, may require confined space entry. This is subject to specific regulation in some regions. Confined space entry should not occur unless: • There is no practicable alternative. • The activity is covered by a Permit-to-Work, including gas-testing and a stand-by person. • The vessel is adequately isolated. Where confined space entry involves a vessel that has contained leaded aviation gasoline, specific guidance should be followed. Working at heights Some filter vessels are mounted at a height above the ground that makes a fall during maintenance a potential hazard. This is best addressed by providing an adequate access platform around the vessel. Working at heights from which a fall may cause personnel injury should not proceed unless: • A fixed platform is used with guard or hand rails, or • Fall arrest equipment is used, and • Persons are competent to carry out the work. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 17 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 75 Chapter 18 Recommendations for operation of filter vessels This chapter provides recommendations to operators of filter vessels. Commissioning Upon receipt of a new vessel the purchaser should satisfy himself that the vessel complies with the requested specification. Subsequent set-up, installation and initial commissioning procedures (including vessel flushing) should be in accordance with manufacturer’s recommendations. Filter/water separator, filter monitor, microfilter and dirt defence filter installations and their associated pipework should be designed to prevent the vessels draining either partially or completely during normal operation. It is especially important that filters are never operated unless the vessel is full of fuel. If air is present in a filter housing, the atmosphere above the jet fuel could be flammable in hot climates. The taking of routine samples may result in air being introduced into the filter vessel. Whenever a filter vessel is less than full, it should be refilled slowly before being operated, see Refilling of vessel with fuel after opening. During the installation of any filter vessel it is important that correct vertical and horizontal alignment is achieved to ensure that free water and particulate matter can be drained from sample points and are not trapped in “dead” areas of deck plates, sumps or pipework. Correctly aligned vessel systems minimise the risk of microbiological growth. Checking for electrical continuity In an electrostatically charged environment, such as that found inside a filter vessel during fuel flow, conductive (usually metallic) components that are not in electrical continuity can accumulate significant electrostatic charge. (Conductive items that are not in electrical continuity are known as “unbonded charge collectors”.) The electrostatic charge can accumulate to the point where destructive and potentially incendiary discharges occur. For all vessels the resistance between all metallic components and the reference point (e.g. the external vessel support foot) should be less than 10 ohms. This is relatively easy to measure and ensures that all the conductive components are well connected. This provides a large safety margin because the voltages are high and the currents are small in electrostatic charging. There must be no unbonded charge collectors (electrically isolated components) in a vessel used to filter aviation fuel. This can be confirmed by testing using the method described in Annex L. If testing indicates that any metallic (conductive) component is electrically isolated then the system should not be returned to service until this is remedied. Filter element installation It is important to follow the manufacturer’s recommendations and local operating procedures when handling filter elements. Care should be exercised to keep them scrupulously clean during installation. It is particularly important to ensure that filter elements are installed with the correct torque (using a torque wrench) in accordance with manufacturer’s recommendations to prevent fuel bypassing the elements. The installation torque should be applied to the element (screw-based) or element installation nut (open-ended) before the spiderplate is installed. It is recommended that when old elements are removed and new ones installed, the elements being removed are carefully inspected. Much can be learned from the state of components Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file18 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 76 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Recommendations for operation of filter vessels that have been in service – leopard spotting of filter/coalescer elements indicates microbiological activity, heavy particulate deposits result from excessively dirty fuels being handled and, subtly, fine white particles on the cotton socks of filter/coalescers indicate salt has been removed from the fuel. All new filters being fitted should be checked for structural and dimensional integrity paying particular attention to the rigidity and positioning of endcaps. Closure of vessel lid When securing the vessel lid it is important to evenly tension the bolts to the correct final torque. Uneven or incorrect bolt tensions cause the gasket to not seat properly and the end result will be a lid that is likely to leak in service. It is recommended that the following procedure should be used: a) Check condition of sealing ring round the opening of the filter vessel. Replace if it shows signs of deterioration. O-ring type seals should be replaced after every four compression cycles. Replacement gaskets should be provided by the filter manufacturer or their authorised representative only. Note: Petroleum jelly may be used sparingly on the vessel seals. b) Carefully inspect condition of cover securing bolts, nuts, washers and, if of a pivoting design, the bolt pivot assemblies and housings for signs of deterioration such as corrosion, distortion or other damage. Any damaged items are to be replaced with new ones supplied by the filter manufacturer or their authorised representative. c) Close filter vessel cover and tighten bolts evenly to approximately one third of the final torque, working on diametrically opposed bolts. Repeat the tightening sequence in at least three more steps to the full torque using a calibrated torque wrench. Finally retighten adjacent bolts using the torque wrench. The final torque setting should be that recommended by the filter vessel manufacturer. Over-length tools should not be used when tightening the vessel’s cover bolts or nuts. Refilling of vessel with fuel after opening EI 1596 (section 2.6) includes the recommendation that for new vessels “A fitting for a narrow bore (25 mm, 1 in.) filling line should be provided either in the filter vessel inlet pipework (for the filling line to connect either side of the gate valve), or in the base of the filter upstream of the filtration stage, as agreed between the purchaser and manufacturer.” Controlled filling of vessels after installing elements is critical to limit static charge generation and minimise the possibility of fire or explosion. Controlled gravity feed is recommended where applicable (liquid level of tank should be above that of filter vessel). Where pumping is unavoidable (e.g. from underground tanks) the flow should be as per filter element manufacturers’ recommendations. New installations should consider incorporating slow-fill lines (small bore piping), see EI 1596. During filling, the correct operation of the automatic air eliminator should be verified. After filling, the integrity of the cover seal arrangement should be confirmed by applying pump pressure while the joint is carefully examined. Uncontrolled filling of empty filter vessels with fuel may result in internal filter fires. Differential pressure The measurement of the differential pressure across a vessel is used to determine the status of the elements within. It is therefore imperative that differential pressure checks are made, logged and analysed. The differential pressure across a vessel is measured using a piston gauge connected to pressure-sensing lines up and downstream of the vessel. It is important that this gauge, e.g. the Gammon gauge™, is regularly checked for proper functioning (e.g. free movement of the piston). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 18 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 77 Handbook on equipment used for the maintenance and delivery of clean aviation fuel A sudden drop in the differential pressure (at the same operational flowrate) or a drop in the rate of increase of differential pressure should be investigated as either may indicate that the elements have ruptured or otherwise failed. Flow rates It is recommended that filter vessels be operated in accordance with manufacturer’s recommendations. Minimum flow rates should also be in accordance with manufacturer’s recommendations. Housekeeping It is important to maintain the filter system in satisfactory order by following the required quality control and inspection and maintenance procedures. Reference should be made to the most recent editions of JIG 1, JIG 2 and ATA 103 for further information. Some key issues and procedures covered by those publications include: • Daily sump drains under pressure. • Recording and correcting filter differential pressure at maximum operating flow rate. • Filter membrane tests downstream of the filter vessel. • Changing filter elements when either maximum differential pressure has been reached or maximum service life if sooner. • Any contra indications observed during any routine check or inspection that should be investigated. • Annual, documented internal vessel inspections. • The inspection and testing of Teflon™ coated and synthetic separator elements. • Maintenance of accessories in line with manufacturer’s recommendations. Internal inspections of filter vessels Reference should be made to JIG 1 and JIG 2 for recommendations regarding the annual internal vessel inspections. The main items covered by those documents are: • Cleanliness of the vessel. • Element appearance. • Correct installation of elements and torque setting. • Condition of element seats/sealing faces. • Condition of internal lining. • Checking of continuity. • Condition of cover seal. • Replacement of damaged or contaminated elements. • Testing of separator elements. • Checking of vessel fittings (air eliminator, relief valve, sump water detector/float mechanism etc.) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file18 is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 78 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Recommendations for operation of filter vessels Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 18 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 79 Chapter 19 Service life of filter elements This chapter briefly describes the options available to the user in determining when to replace elements. Provided the operating conditions are compatible with a particular manufacturer’s elements, the operator chooses which elements to use as replacements (vessels have universal fittings to allow interchangeability of elements). Manufacturer’s recommendations Each manufacturer issues recommendations on service life intervals. For instance, currently all manufacturers recommend that filter monitor elements should not be used for more than 12 calendar months. For filter/coalescer elements, the recommendations of manufacturers vary (between one and two years), ATA 103 specifies service life of one year, with possible extension based on six-monthly single-element testing, and JIG guidelines enable use for a maximum of three years. Operators should ensure that they know the recommended changeout interval for the particular products that they are using so that they can plan the changeout process. Manufacturers may also issue recommendations on maximum shelf-life of products. Further confusion may arise as manufacturers also recommend the shorter of the time-based service life and a performance-based service life. For FWS the performance-based service life is when the differential pressure across the vessel exceeds 22 psi (1,5 bar). For filter monitors it is when the differential pressure reaches 22,5 psi (1,55 bar), (unless otherwise specified by the manufacturer). Elements will require changing because of an increase in differential pressure much earlier than one, two or three years if the fuel is not clean and dry. A key factor affecting actual operational life is fuel throughput. This is far more important than time. For a given operation, experience will soon indicate typical throughputs that can be expected for given filtration devices. A final point: if operating costs are high from short service life of filter elements, an operator may want to protect the elements from particulate matter by installing microfilters (see chapter 10) and/or better management of water removal. Operating conditions In several locations the aviation fuel handling systems are clean and dry. Therefore the differential pressure across filter vessels does not increase significantly during the recommended time-based service life for elements. In these cases it is reasonable to ask why they should be changed. The short answer is that there is no technical reason. Elements do not suddenly disintegrate once the manufacturer’s recommendation for service life has been exceeded. If elements continue to be used beyond this, the operator assumes greater liability for the performance of the filtration system. corrected differential pressure Is the measured pressure across the vessel at the measured flow rate, after correcting the rated flow of the vessel. Blocked elements Under no circumstances should elements be operated when the differential pressure of the vessel exceeds the manufacturer’s recommendations. Qualification testing requires proof that elements can operate many times higher than this to ensure a reasonable factor of safety is available for occasional short-lived high pressure transients (surges). Operating at higher pressures effectively removes the safety margin. Further, there is no practical incentive for extending the life of elements beyond their recommended differential pressure maximum. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 80 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Service life of filter elements Short life of elements (rapid differential pressure rise) Many operators complain about the short life of their filter elements without realising the implications of what has happened. Filters are designed to stop the transmission of particulate matter and free water. When they do so they become less permeable and resistance to fuel flow increases with a consequent rise in differential pressure. A rapid rise in differential pressure indicates that: 1. 2. the filter has removed contamination, and the fuel was contaminated. This requires that the filters be changed immediately and there to be an investigation to find the cause of the contamination. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 19 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 81 Chapter 20 Disposal of used filter elements General considerations Used filter elements are classified as hazardous waste because they contain some amount of fuel. Hazardous waste has to be carefully disposed of in a responsible manner – in many cases there will be local legislation governing this process that will have to be observed. Some filter manufacturers supply elements that include components that can be recycled after collection or that can be crushed for easier disposal. Users are encouraged to consider this when selecting elements. Elements that have been used in aviation fuel handling systems containing leaded aviation gasoline (such as Avgas 100 / 100 LL) could contain sludge or scale that contains toxic lead compounds. Such elements require specialist disposal. Further information may be found in Innospec Environmental Ltd publication Leaded gasoline tank cleaning and disposal of sludge. Storage Used filter elements should be stored in a suitable container prior to collection for disposal. The design and size of the container depend upon the number of elements stored and the storage duration. Storage of a small number of used elements for a short period could be in an open top metal drum. A larger number of elements, which are collected less frequently, will require a more elaborate storage arrangement. Storage should not allow any leakage of fuel into the environment. Storage arrangements should also be adequately ventilated to prevent an explosive atmosphere developing. All storage containers for used filter elements should be appropriately marked to show their hazardous content. Such markings must comply with local regulations where applicable. Disposal Where local legislation dictates the disposal process, this must be observed. Used filter elements are typically disposed of by specialist contractors who will collect and transport them to a waste treatment plant for high temperature incineration. In some cases, used filter elements may be disposed of in landfill sites but only after treatment. Users of filter elements will need to use a specialist waste disposal contractor for these services. Filter suppliers may be able to recommend such a company. Contractors collecting used elements for disposal should provide a record of the dates and number of elements removed from the operating site, and a written declaration that they will be properly disposed of and in accordance with any relevant legislation. Users should execute their duty of care to ensure that the contractors carry out this service in a proper and professional manner. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This20 file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 82 Chapter the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Disposal of used filter elements Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Chapter 20 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 83 Annex A Definition of ‘the industry’ FUEL SUPPLY COMPANIES (at airports) FUEL USERS - Major international airlines - Regional/national airlines - General aviation - Military - Major international oil companies - National oil companies - Into-plane agents - Fixed base operators - Airlines - Consortia of above - Airport authorities - Oil companies - Consortia - Airlines ANALYTICAL FUEL TESTING LABORATORIES FUEL ADDITIVE SUPPLIERS FUEL HANDLING EQUIPMENT/ COMPONENT MANUFACTURERS/ SUPPLIERS - Fuelling vehicle manufacturers - Filter manufacturers - Other hardware manufacturers HYDRANT OWNERS/ HYDRANT OPERATORS REFINERS - Major international oil companies - National oil companies - Independent companies THE INDUSTRY ACADEMIA CONSULTANTS AIRCRAFT ENGINE MANUFACTURERS (original equipment manufacturers) REGULATORS (Governments) - National Aviation Authorities AIRFRAME MANUFACTURERS ‘OVERSIGHT’ ORGANISATIONS (including standards developing organisations (SDO), trade associations (TA) and professional societies (PS) - API - ASTM Int - ATA - CRC - EI - IASH - IATA - JIG - NATA - SAE FUEL SPECIFIERS - UK MoD via QinetiQ - ASTM International - JIG - GOSTSTANDART - Others regionally (SDO/TA) (SDO) (TA) (PS) (SDO/PS) (PS) (TA) (SDO/TA) (TA) (SDO) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This A file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 84 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex A the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 85 Annex B Aircraft engine fuel filters and engine tolerance of particulate matter and free water Key points of this Annex • Filtration used in aviation fuel ground handling systems is designed to permit no more than 0,15 mg/l particulate matter down to a nominal size of 1,0 µm, and free water to a maximum of 15 ppmv. • The use of aircraft engine filters provides protection against potential debris from aircraft fuel tanks and fuel systems, airborne debris entering aircraft through vents and large-sized particulate matter that may have been uplifted to the aircraft as a result of a rare failure of the into-plane filtration (including hose-end strainer). • The rating of filters used on-board aircraft to protect commercial transport engines (such as those operated by major international airlines) is in the range of 25-40 µm absolute, and as small as 10 µm nominal. The rating of engine fuel filters used in military aircraft is similar. • The rating of small specialist turbine engine filters can be as small as 10 µm absolute and 7 µm nominal. • Aircraft engine fuel-wetted components are tested for operability during exposure to specified levels and types of contaminants in test fuel during engine design/certification. • There is a significant factor of safety between the performance of aviation fuel handling filtration (both particulate matter and free water) and aircraft engine tolerances. This is of paramount importance in providing operational contingency when dealing with a rare fuel contamination event. It is certainly not the intention of this annex to suggest that fuel handling system filtration should be relaxed. • This annex is provided for information only. Chapter 3 includes details of some of the operational effects of fuel contaminants. These include the blockage of aircraft engine fuel filters by particulate matter or microbial growths and potential engine flameout (caused by fuel starvation and in extreme situations by bulk water). The purpose of engine fuel filters is to prevent particulate matter from getting into the close tolerance fuel control and injection components of the engine fuel system. Small hard particles have been noted as being of particular concern as they can erode surfaces (increasing tolerances) in fuel-flow control spool valves, hindering performance or even jamming the valve. Engine fuel filters protect specific components and therefore have a range of nominal ratings as shown in Table B1. These filters are specified by engine and airframe OEMs (original equipment manufacturers) and performance tested by suppliers or component assemblers. Some use Beta ratios (see Annex E) whilst others use gravimetric methods but they are rarely tested directly by the engine or airframe OEM. Note: the closest tolerance in engine hardware encountered today is a nominal 10 µm. The 1 µm nominal EI filter specification limits provide fuel suppliers with an order of magnitude safety margin. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This B file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 86 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Table B1: Ratings of different engine filters Component Nominal filter rating, microns Absolute filter rating, microns Hydro mechanical unit (fuel control) 10 35 Servo 270 Actuator inlet 230-270 Actuator outlet 230-270 Fuel flow inlet 50 Electro hydraulic servo valve 70 EHSV/HMU 154 HMU EHSV 74 There is also an “air-worthiness” engine component test requirement for continuous operation at 2 mg/l of a specified test dust. When compared with the EI filter performance limits of <0,15 mg/l, another contaminant mass safety margin is apparent. Dissolved water in aviation fuel condenses out as the fuel cools at higher altitudes. This is a normal situation which the fuel handling systems on board aircraft are designed to accommodate. Features include aircraft fuel tank design, with water draining to low points, and the use of fuel scavenging/pumping systems within fuel tanks. The scavenge pick-up points are typically sited at various low points in the wing tanks and move any free water generated to the engine inlet. These low levels of free water pass harmlessly through the engines. The free water created by fuel changing temperature is not a significant concern, because it does not happen all at once, or at least does not reach the pump inlets at the same time. The main concern is the potential for uplifting large amounts of water that could cause a flameout during takeoff roll or climb. Within general aviation there is a greater variety of aircraft engine types, which in addition to turbine engines include spark-ignition piston engines that operate on aviation gasoline and compression ignition (diesel) piston engines that operate on jet fuel. Further details of engine fuel filter specifications and the engine performance testing using fuel containing contaminants should be sought from relevant engine manufacturers. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex B the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 87 Annex C IATA guidance material for fuel contamination limits Introduction The following information is taken, with permission, from IATA Guidance material for aviation turbine fuels specifications, Part III Cleanliness and handling, 5th edition, 2004. The recommendations of that publication are for fuel delivery into aircraft to be protected by a system of quality control. This includes systematic and regular spot and/or continuous monitoring to test the quality and cleanliness of the fuel and the efficiency of the fuel supply system defence. Fuel is required to be sampled regularly and tested for the presence of particulate matter and free water. The IATA recommendations are provided, in part, to ensure safe continuity of fuel supply, and are minimum recommendations. Operators are encouraged to ensure these are comfortably met within the constraints of their particular operational conditions. IATA contamination limits Fuel cleanliness is required to be assessed for each aircraft refuelling. The refuelling process does not permit elaborate laboratory analysis to be carried out on each delivery and so simple, rapid tests are required that constitute a final check on a system that is intensively monitored and controlled. The IATA recommendations for such tests are shown shaded in Table C1. In addition, more stringent testing of fuel cleanliness is required on a monthly and six-monthly basis. These tests are used to confirm that the equipment employed is effective in maintaining fuel cleanliness. For those tests, two limits are provided: ‘Notification’ and ‘Rejection’. The IATA recommendations for such tests are also shown in Table C1 (not shaded). The guidance also provides recommendations for actions that a fuel supplier should take if notification and/or rejection limits are exceeded. The recommendation is also included that a Gravimetric test should be carried out on all new or re-commissioned vehicles, when new hoses or filters are fitted and on new hydrant lines and storage tanks before commissioning. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This C file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 88 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Table C1: IATA contamination limits (content of table reproduced with permission of IATA) Contaminant When sample is to be taken Visual inspection of fuel in glass jar (minimum 1 l) Clear & Bright Monthly ASTM D 2276 or IP 216 (5 l samples) using colorimetric procedure No unusual result (colour difference should be two or less) Six-monthly ASTM D 2276 or IP 216 (5 l samples) using Gravimetric procedureA Notification 0,2 mg/l Visual inspection of fuel in glass jar (minimum 1 l) Free water Before refuelling the aircraft Visual inspection and water detectorB Free water Rejection 1,0 mg/l Clear & Bright 30 ppm maximum at the temperature of delivery Daily Visual inspection of fuel in glass jar (minimum 1 l) Clear & Bright Monthly ASTM D 2276 or IP 216 (5 l samples) using colorimetric procedure No unusual result (colour difference should be two or less) Six-monthly ASTM D 2276 or IP 216 (5 l samples) using Gravimetric procedureA Notification 0,2 mg/l Particulate matter Hydrant Servicer or Cart Limit After loading the refueller Particulate matter Refueller Truck Test Method During each fuelling Rejection 1,0 mg/l Visual inspection of fuel in glass jar (minimum 1 l) Clear & Bright Visual inspection and water detectorB 30 ppm maximum at the temperature of delivery Note A – A Gravimetric test may not be required if into-airport storage and out-of airport storage filtration uses FWS qualified to EI 1581, storage tanks are fully epoxy lined, have coned down bottoms and floating suctions and into-plane filtration uses FWS qualified to EI 1581 or filter monitors qualified to EI 1583. The six-monthly Gravimetric test may not be required if the monthly colorimetric tests produce a colour rating of 2-Dry or less. Note B - This can be by the use of the Shell Water Detector™, Velcon Hydrokit™, Mobil Moisture Detector™, Aqua-Glo™, POZ-T™, YPF Capsulas detectoras de agua libra, Aquadis or Aqua Indica. For further information on these detectors see Annex D. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex C the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 89 Annex D Traditional methods for the assessment of fuel cleanliness Traditional methods for the assessment of fuel cleanliness This annex includes brief descriptions of the following commonly used field assessments of fuel cleanliness (where applied the test methods themselves should be followed): ASTM D 4176 Standard test method for free water and particulate contamination in distillate fuels (visual inspection procedures) • Clear and bright (ASTM D 4176) • Gravimetric (Millipore) analysis (ASTM D 2276/IP 216) • Colorimetric analysis of Gravimetric membranes • Aqua-glo (ASTM D 3240) • Shell Water Detector™ and Velcon Hydrokit™ • POZ-T™ Clear and bright (ASTM D 4176) ASTM D 4176 describes a test that is well known in the field as the “clear and bright” test (C&B). Whilst the fuel may typically have a colour from water white to pale straw, the test aims to visually identify any water droplets or dirt particles in the fuel. Note that it is impossible for the human eye to see droplets and particles much less than about 40 μm in diameter so this is not a very sensitive test unless the number of droplets and particles are so great that the fuel appears hazy. However, it is a very useful, quick and easy test to carry out. One important precaution in performing this test is to ensure the sample test jar is clean. This may seem an obvious statement but there have been many instances in the field where dirty, unsuitable containers have been used leading to incorrect assessments. Note also the following advice: • Air bubbles may sometimes be slow to clear - the sample should therefore be allowed to stand for at least one minute before making an assessment. • Swirling the sample to create a vortex concentrates contaminants in the middle of the bottom of the jar facilitating the assessment. • If the sampling tap is some distance from the bulk fuel to be sampled it will be necessary to purge sufficient fuel to ensure that the sample taken is representative of the fuel batch. • With experience, an operator can differentiate between water and particulate matter. Figure D1: Examples of the clear and bright test Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This D file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 90 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Gravimetric (Millipore) analysis (ASTM D 2276/IP 216) Quantitative assessments of particulate contamination in fuel can be made using Gravimetric membrane filter analyses for particle sizes >0,8 μm described in method ASTM D 2276 or IP 216. The test is often called the “Millipore” test as the Millipore company was the first to supply the delicate membranes and test kit that are used in this type of analysis. The principle of the method is shown in Figure D2 and some important points to note are: • The ASTM/IP recommended minimum volume can result in pad-blocking in the case of dirty fuels and therefore it is recommended that a smaller volume be sampled. In this case it is important to record the actual volume sampled. • Pads can be purchased as “matched weights” so that it is not necessary to know the original pad weights. When matched-pads are not used it will be necessary to weigh both pads before and after use and to note which pad is the “working” and which the “control”. • Not all pads are compatible with aviation fuels and a large range of pad filtration ratings is available – it is recommended that the user establishes that the pad is rated at 0,8 μm, is the correct diameter for the pad holder and is suitable for use with aviation fuels and additives. (Note membranes can swell and disintegrate when DiEGME is present in fuel.) • ASTM/IP precision statements only apply to total particulate loadings of up to 2 mg/l (calculated on a 51 sample). Anomalous results can be obtained for very dirty fuels. • Anomalous results can occur if the membrane weights change during the analysis or if particulate matter leaks through to the control membrane. If there is any doubt about a gravimetric result then it should be repeated. • The analysis involves sampling and then laboratory processing of the pads to obtain accurate results. This takes time and the method cannot yield instant values. Colorimetric assay of pads for a real time result is an option and described below. • The method does not measure water contamination. A minimum of 1 gal. or 3,78 l sample Or record the volume filtered if membrane plugs Working membrane, W Control membrane, C $RIED IN OVEN THEN WEIGHED 0ARTICULATE -ATTER ,OADING = 7EIGHT OF 7 - 7EIGHT OF # 3AMPLE 6OLUME !SSUMES THAT BOTH MEMBRANES REMAIN THE SAME WEIGHT !SSUMES THAT PARTICULATE LOADING MG TOTAL Figure D2: Principle of Gravimetric (Millipore) analysis Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex D the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 91 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Colorimetric analysis of Gravimetric membranes The membranes or pads used above are white in colour and any build-up of particulate matter on them will discolour them. ASTM/IP test methods also include a visual assessment method (of wet or dry pads) to assist in more timely analysis of fuel cleanliness. The working membrane is visually matched in terms of colour and shade to samples contained in a commercially available booklet giving a result in terms of: a letter - A, B or G depending on the coloration, a number - 1-10 with 10 being the most intense. This method is a useful rapid diagnostic tool but does not yield quantitative data. Aqua-glo (ASTM D 3240) This method measures free water in a 500 cm3 sample of aviation fuel quantitatively up to 12 ppmv. By reducing the sample volume the range of application can be extended but each time the volume is reduced, the method will suffer progressive reduction in accuracy. Nevertheless, with most fuel specifications mandating 15-30 ppmv free water as a maximum limit, the method is relevant. The analysis can only be carried out by line sampling as the fuel needs to be forced through the sensitive pad. The pad is then placed in a special detector where the quantitative measurement is made. This method is used extensively in laboratory testing of water separator/removal equipment. Shell Water Detector™ and Velcon Hydrokit™ Two proprietary methods are available for the rapid detection of free water in aviation fuels. They are both based on a colour change in the supplied medium on contact with very low levels of free water (<30 ppmv). The methods do not have formal ASTM or EI protocols but each is easy to use and instructions are included with the kits. Both methods require a fuel sample to be taken in a suitable container (sampling precautions) and then transferred to the sensitive media. Note: They provide non-quantitative, go-no-go advice in terms of levels of free water. They do not measure particulate contamination. POZ-T™ This is a method commonly encountered in the former Soviet Union (especially in Russia). It combines the colorimetric capabilities of the above water detectors and the particulate membranes and as such should be viewed only as a go-no-go method. The device is used in a similar way to the water detectors in that a fuel sample is taken and then transferred to the sensitive media. There are two media layers one of which produces a colour change if free water is present, and one that is white and indicates the presence of particulate matter by the development of dark spots. Other water detection kits There are also other water detection kits that are applied regionally, including the YPF Capsulas detectoras de agua libre in South America and Aquadis and Aqua Indica in India. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This D file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 92 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex D the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 93 Annex E Filtration ratings, absolute, nominal and Beta ratios Filtration Ratings, Absolute, Nominal and -Ratios. Filter performance or rating may be assessed on the basis of ability to remove particles of a specified size from a flowing medium. The National Fluid Power Association (NFPA) defines an Absolute Rating of performance as: “The diameter of the largest hard spherical particle that will pass through a filter under specified test conditions. It is an indication of the largest pore opening in the filter.” Note 15: From the Laplace Equation which relates the maximum pressure developed to form a bubble of gas at an orifice immersed in a liquid as a function of the orifice size and the surface tension of the liquid, the Bubble Point test determines the maximum pore size in a filter medium. Practically this can be done using test methods such as the ASTM E 128 Standard test method for maximum pore diameter and permeability of rigid porous filters in laboratory use. Porometer instruments are commercially available to measure the full pore size distribution of filter media. These instruments measure the downstream gas flow as a pressure ramp is applied to the upstream side of a sample that has been soaked in an organic liquid with an extremely low surface tension. The onset of downstream gas flow is equated with the “Bubble Point” and from the Laplace Equation the maximum pore size is computed. The instrument then continues to monitor the gas flow rate as a function of progressively increasing gas pressure until all of the liquid has been blown out of the sample to yield the distribution of pore sizes. Thus, filter media with exact and consistent pore sizes such as Millipore membrane filters will have an absolute rating. A complication in the testing and application of such filters is that particles with a distribution of sizes will soon result in the formation of a surface cake on the upstream side of the filter (the side first exposed to the flowing liquid). This cake effectively becomes the filtration medium changing the filtration mechanism from surface filtration to deep-bed filtration. Deep-bed filtration invariably results in an improvement in particle interception efficiency and the filter rating will appear to improve progressively. The question then arises“ at what point in testing is the Absolute Rating established?” Thus, it is preferable with such filters to use the supplementary definition for Absolute Rating – “...the largest pore opening in the filter.” This can be determined by a Bubble Point Test15 More commonly, filtration media comprise woven and non woven papers, felts and cloths, all having a wide range of randomly distributed pore sizes. With such media it is not possible to assign an Absolute Rating and when done so, is meaningless. Besides operational flow and pressure conditions, the randomness of the weave and the depth of the filter will determine the particle size cut off point or maximum size of particles transmitted by the media. Performance can therefore only be described in terms of a Nominal Rating defined by the NFPA as follows: “An arbitrary micron value assigned by the filter manufacturer based upon removal of some percentage of all particles of the given size or larger. It is rarely well defined and not reproducible.” At present the only relevant standards are MIL-F-5504A and MIL-F-5504B Filters and filter elements, fluid pressure, hydraulic micronic type where version A defines the Nominal Rating as the removal of 98% of particles of size larger than the quoted size and version B, the removal of 95% of those particles. This inevitably means that such filters will allow a few particles larger than the rated size value to pass through the filter but it also means that many particles smaller than that size will be intercepted albeit at progressively lower efficiencies. One further term that may be encountered in defining filtration efficiency is that of Beta Ratio (ß). This is defined as: = Ni/Ne where: Ni = The number of particles of a given size and larger in the influent Ne = The number of particles of that same size and larger in the effluent. It follows that the higher the Ratio the greater the efficiency of the filter. For a given particle size, x, the Filtration Efficiency, Ex is given by: E x %� E x 1 u100 Ex This type of performance testing requires the use of particle size analysis equipment and this is currently not specified in EI filtration publications. (NOTE: A Ratio value of 200 represents a calculated efficiency of 99,5% and is considered in many industries to represent performance sufficiently close to 100% efficiency to be considered Absolute.) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This E file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 94 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex E the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 95 Annex F Clay treatment What is clay treatment? Aviation fuels are made up of a variety of molecules that contain primarily carbon and hydrogen. These burn to produce energy, carbon dioxide and water vapour. The presence of trace levels of other atoms such as oxygen, sulphur or nitrogen in the hydrocarbon material is generally unavoidable and introduces effects that are undesirable. Energy yield may be reduced, thermal stability deteriorate, but more relevant to this publication – particulate matter filtration and water separation may be compromised. When aviation fuel is transported through multi-product pipelines the fuel may acquire trace additives and other “polar” materials from previous consignments of other fuels, e.g. diesel. These additives can be surface active compounds (otherwise known as surfactants) which may affect a number of fuel properties such as thermal stability and especially filter/coalescer performance, (see Annex G). Such surfactants may also be present in fuels produced by certain refinery processes. Clay treatment of aviation fuel has proven to be an effective means of removing these surfactants and is used extensively by refineries and some distribution facilities (particularly in the US). How does clay treatment work? Clay treatment is an adsorption process that is completely different to filtration even though it is sometimes referred to as “clay filtration”. With its large surface area (approximately 110 m2/g (1 200 ft2/g), and affinity for polar materials, surfactants are adsorbed on the surface and within the porous structure of the clay. Removing surfactants improves the water separation properties of aviation fuels. Clay may also remove unwanted colouration from the fuel. How is clay treatment applied? This annex relates primarily to cartridge-type clay treatment units as opposed to units which utilise bulk clay (used mostly in refinery and large fuel depot applications). Clay cartridges are available as either bags or canisters for installation in large vessels. Compared to canisters, the bags are typically less expensive, and contain more clay, but can be difficult to install. The clay used in the bags and canisters is typically low volatile matter (LVM), 50 - 90 mesh, attapulgite clay mined in Attapulgus, Georgia. (Note coarser 30-60 mesh can also be supplied.) LVM clay has better water tolerance and therefore less tendency to cake or agglomerate, compared to regular volatile matter (RVM) clay (used primarily in bulk units). Initial differential pressure is typically low for a clay treatment unit containing fresh clay (approximately 5 psi). Use of clay with a larger mesh number (smaller clay particles and more compact structure) causes higher initial and accumulated differential pressure throughout its service life, however, it can provide substantially more capacity. Aviation fuel flow through cartridge-type clay treatment units should be 19 - 26 l/min (5 - 7 gpm) per 178 mm x 457 mm (7 in. x 18 in.) element. Lower jet fuel flow rates result in longer contact times, which increases clay effectiveness. What are the issues? Clay treatment also removes additives such as static dissipator (SDA) and corrosion inhibitors, which may be required in the fuel by specification or customer agreement. Therefore, clay treatment vessels should be located upstream of any additive injection points, or re-dosing may be necessary. If cartridges are not installed properly, aviation fuel can bypass the clay. Without appropriate maintenance, there is a possibility that the clay bags or canisters can suffer structural failure, releasing clay into the aviation fuel stream. Some sites have installed a microfilter immediately downstream of the clay treatment vessel to intercept any migrating clay. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This F file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 96 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 The effectiveness of clay treatment should be regularly monitored. This is best done by making comparative measurements of fuel properties that relate to the presence of surface-active materials upstream and downstream of the clay treater. Fuel properties that relate to the presence of surface-active materials Conductivity can be used if the upstream fuel value is significant (>25 pS/m). Downstream conductivity should be lower than the upstream value. 2. Water Separability: If measured by MSEP (ASTM D 3948), the downstream value should be higher (better separability) than that for the upstream fuel, and close to 100. 3. Interfacial Tension: The downstream value should be higher than the upstream fuel, unless the upstream fuel value is close to that of pure fuel. 4. The differential pressure reading should also be no more than 15 psi at rated flow, to confirm that bed plugging (blocking of porous structure) has not occurred. ASTM D 3948 Standard test method for determining water separation characteristics of aviation turbine fuels by portable separometer. 1. If any of the conditions in 1-4 above are not met, then the clay bed is probably exhausted and should be changed. Furthermore, one or more of the following observations from a FWS located downstream of a clay treatment vessel can also indicate that the clay bed is exhausted: Note 16: L.Z. Pillon, 2001, Surface active properties of clay-treated jet fuels, Petroleum Science & Technology, 19, pp 1109-1118. This paper highlights the tendency for some surface-active components in the fuel to preferentially adsorb at the fuel/water interface rather than on the clay surface. • Disarmed filter/coalescer (surfactants not being removed) • Significant volume of water drains (wet system/clay) • Brown water drains (surfactants not being removed) To maximise the life of clay cartridges, care should be taken to minimise exposure to water and rust or other particulate matter. Water is attracted to the clay. Over time the water can disarm the clay and potentially flush adsorbed surfactants from the clay media into the aviation fuel stream (Pillon, 2001)16. Excessive water contact can also cause flow channelling and clay dispersion, resulting in high particulate content in the aviation fuel. If there is any chance of high water content in the aviation fuel to be clay treated, it is recommended to use coarse water separators or hay-packs upstream of the clay treatment vessel to protect the clay bed. In refineries salt driers are often used. Particulate matter can disarm the clay by occluding adsorption sites on the surface of, and within, the clay structure. Exposure to rust or particulate matter also plugs the clay bed increasing the differential pressure. If there is any chance of high particulate matter content in the jet fuel to be clay treated, it is recommended to install a microfilter upstream of the clay treatment vessel to protect the clay bed. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex F the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 97 Annex G Filter/coalescer disarming Filter/coalescer disarming Water dispersed in fuel is not very stable and will naturally separate over a very short time. However, if the droplets are very small (micronic in size), this will take too long because of their very slow settling velocity (many days – see chapter 3) and so a separation device such as a coalescer has to be used. The processes that occur within the coalescer are complex and outside the remit of this publication, but essentially the droplets of water are made to contact fibres within the coalescer, and after multiple collisions they coalesce into larger droplets that can be easily settled out by gravity. The presence of “surfactant” molecules in either the fuel, or the water phase, can destroy this process rendering the device useless. In Figure G1 a surfactant, known as Aerosol OT, was added to jet fuel and the effect on water transmission through a coalescer measured. As can be seen, below 0,4 mg/l, (an extremely low concentration), coalescence is proceeding satisfactorily with less than 30 ppm water being transmitted. However, at concentrations above 0,4 mg/l Aerosol OT interferes with the coalescence process, and above 0,8 mg/l the negative effects are so dramatic that none of the water droplets are coalesced at all. This effect of surfactants has been termed “coalescer disarming”. & 2 % % 7 ! 4 % 2 4 2 ! . 3 - ) 3 3 ) / . PPMV #/.# !%2/3/, /4 MGL Figure G1: Effect of fuel surfactant level on the water coalescence performance of a commercial filter/coalescer For operators in the field, it is not possible to see the processes occurring within the vessel and pipework, and the only indication that this is happening would be high water transmission readings when using a water detector, or haziness in fuel samples taken downstream. Figure G2 illustrates the difference in water drop sizes and fuel clarity between a normally operating coalescer and one that is disarmed. The photographs were taken looking through a test vessel with windows, showing the space between the coalescer and the separator. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This G file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 98 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 The industry has made many attempts to find ways of dealing with this situation. Tests such as WSIM (Water Separation Index, Modified) and MSEP (Microseparometer) were developed to test coalescence of jet fuel/water mixtures to predict the performance of installed systems. This was partially successful, but it is now known that no single test can predict coalescer disarming because there are multiple mechanisms which can cause it. EI 1581 5th edition has addressed the issues in part by increasing the surfactant content of test fuels to drive the development of more surfactant resistant coalescers. It is not currently known whether this has resulted in products that have improved field performance. Coalescer disarming will remain a challenge for this type of equipment for many years to come, and was the main reason that filter monitors were introduced. Filter monitors are not affected by surfactants in the same way as coalescers and can stop water under conditions where coalescers are disarmed. Good coalescence The phenomenon seems to occur mostly in dry systems! This is probably a consequence of the nature of the coalescer media – there is an affinity between the chemistries of surfactants and the surfaces of the fibre media – that results in a concentration of trace surfactants from the fuel onto the media. The build up of surfactants can be released when free water passes through the system, which can cause the water to form very fine droplets that pass through coalescers and separators. In laboratory testing, disarmed coalescers often recover coalescence performance when the surfactants are “washed off”, indicating the reversible nature of the phenomenon. This is not an option for field use. Visual water coalescence testing of used coalescers was once quite popular for determining if coalescers were disarmed. The difficulty in interpreting the results when used coalescers from dry service showed a small puff of dispersed water, followed by good coalescence performance, is one reason this testing has fallen out of favour. What can an operator do? Disarmed coalescer • Always be aware of the limitations of FWSs. • Assume the filter/coalescer can be disarmed! • Check the quality of the fuel downstream of the FWS regularly. • Check samples from the sump for hazy fuel. • In the future consider applying electronic sensors as an independent check on the integrity of FWSs. Figure G2: Photographs to show the nature of filter/coalescer disarming by surfactants dissolved in jet fuel Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex G the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 99 Annex H Super-absorbent polymer (SAP) As noted in chapter 9 the water removal performance of filter monitor elements that comply with the mandatory requirements of EI 1583 5th edition may become degraded to a level that is unacceptable if the design is sensitive to certain operational parameters. The removal of water by absorption relies on chemical interactions that can be disrupted by extraneous agents. The performance of filter monitor elements that comply with the mandatory requirements of EI 1583 may also be sensitive to certain environmental or operational conditions, such as low temperatures or high salinity of free water. Filter monitor elements may differ in design in the selection of filtration and water absorbing materials. Different water absorbing materials may respond differently to field parameters such as fuel/water temperature, the salinity of free water, free water, and the presence of trace contaminants. Further, the propensity of filter monitor elements for releasing SAP into the fuel stream (SAP migration) can depend upon materials selection, element design, environmental and operational factors. This annex provides details regarding issues suspected or known to impact the performance of filter monitors in service. It is recommended that these issues be addressed between the user and manufacturer to ensure that the performance capabilities of the filtration equipment are suitable for the intended application. Current designs of filter monitor elements incorporate SAP to provide water-removal and water-stopping performance. Under many different operational conditions and over many years of use, the technology has proved reliable in preventing the uplift of contaminated fuel to aircraft during refuelling. However, there have been instances of loss in performance of this type of filter that have eluded explanation that would have led to remedies. Known or suspected issues that impact SAP performance: • Water-soluble components - Impure water, such as that containing dissolved salts, is absorbed by SAP more slowly and to a lesser extent than pure water. Filter monitor elements may not be capable of effectively stopping an impure water slug. Operators should use monitors with care if it is possible that the water phase may contain a solute. Note EI 1583 5th edition includes a category of monitor that is qualified using synthetic seawater (all categories are required to pass a 50 ppm water challenge containing 0,5 % NaCl). • pH - The water absorption of SAP can vary with the pH of the water. Note that it is also possible, in principle, for acidic or basic components in fuel to ion exchange with the active sites of the SAP reducing its water absorption capacity. • Cross-linking - Some level of cross-linking is essential in the manufacture of SAP to stabilise it. However, multivalent cations, such as calcium or magnesium (e.g. from seawater), are known to cause additional cross-linking that reduces the ability of SAP to absorb water. There may be a multivalent cation concentration in water above which a filter monitor element cannot stop a contaminated water slug. • Degradation – SAP is known to degrade by a number of mechanisms including those related to thermal, hydrolytic, freeze/thaw cycles, stop-start cycling, low flow and electrostatic processes. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This H file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 100 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 • Temperature response - Water is absorbed by SAPs at rates which vary with temperature. Specifically as the ambient temperature approaches freezing then water absorption rates have been found to decrease. Around freezing a filter monitor element may not stop a water slug depending upon the materials and design of the element. At temperatures below freezing, in the absence of solutes, water (now ice) is removed by a filtration process rather than by absorbency. Testing of filter monitor elements suggests that this issue, by itself, is adequately controlled. However, it is not possible to dismiss temperature as a factor when other challenges are also present. EI 1583 5th edition includes optional performance experiments, covering some of the above topics, that may give additional characterisation of filter monitor element performance under laboratory conditions. Any data generated are requested to be provided to the EI (www.energyinst.or.uk/filtration). Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex H the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 101 Annex I Conversion of filter/water separator vessels for use with microfilter elements Many filter/water separators are used in fuel receipt applications where the risk of contamination by water is minimal but particulate matter loading may be high. It is possible for a FWS to be converted to a microfilter by any of three schemes. FWS vessels with side-by-side or concentrically configured elements These vessels may be converted by installing out-to-in flow microfilter elements on the separator (outlet) stools. A disadvantage of this method is that capacity may be limited because usually there are relatively few separator stools in a FWS vessel. Other disadvantages are based on the fact that microfilter elements are made in relatively few lengths compared with separator elements. Thus, in some situations, either a shorter microfilter than desired has to be selected, or new tie rods of a different length installed to complete the conversion. A preferable method is to install out-to-in flow microfilter elements on the filter/coalescer stools and reverse the direction of fuel flow through the vessel (causing the separator stools to become the inlet). This method combines the benefits of the previous method, while avoiding the disadvantages. Note that items such as flow markings and differential pressure gauge connections require attention when vessel flow is reversed. FWS vessels with end-opposed elements If an element mounting/sandwich plate is fitted between the cover and vessel shell, the conversion should generally be such that the microfilter elements are fitted to the plate at the opposite end. The sandwich plate can then be removed, any hinges being modified to suit. With elements mounted at only one end of the vessel, greater length is available for elements. Accordingly, the flow capacity can be increased or, for a given flow rate, fewer long elements used (vacant ports blanked off). There is less flexibility to do this with side-opening vessels because of reduced access for element installation. Spider plates In modified vessels, where the capped ends of the microfilter elements do not align with the existing spider mounting lugs welded to the vessel, support for the spider can be achieved by adding adjustable bars, capped with rubber sleeves. The electrical resistance between the spider and an earth point on the vessel (not the mounting rods) should be measured to confirm that it is 10 ohms or less. If it is not, a separate bonding wire should be connected between the spider and the original support lug. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This Ifile is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 102 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex I the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 103 Annex J Conversion of filter/water separator or microfilter vessels for use with filter monitor elements A vessel built for use as a FWS or microfilter can, in most cases, be converted for use with filter monitor elements. The following information is applicable to the majority of FWS vessel types. In most cases the design differential pressure rating of the element mounting plate or manifold is lower than the 225 psi (15,5 bar) required for filter monitors. Additional fittings are required to prevent pressure surges from damaging the mounting plate or manifold, which can cause bypassing. Typically, this comprises a pneumatic or electrical switch triggered by a differential pressure of 29 psi (2 bar) and linked to stop fuel flow (e.g. close a valve or stop a pump). The switch should be a ‘lock-off’ type i.e. once it has been activated, it should stay in that position. The reset mechanism should be lockable or accessible only with the use of tools. The arrangement should also include isolating and drain valves to enable simulation of a high differential pressure for routine test purposes. 50 mm (2 in.) and 150 mm (6 in.) conversions For 50 mm (2 in.) nominal diameter elements it is possible to use a manifold designed to accommodate a cluster of five elements which fits onto the original mounting for an 89 mm (3,5 in.) inside diameter open-ended separator element. This arrangement, using as many manifolds as necessary for the required flow rate, together with blanking caps, can generally be used in side opening FWS with an end-opposed coalescer/separator configuration, and also in side-by-side designs where there are sufficient separator mounting stools. With end opening horizontal filter/water separators having end-opposed elements and a sandwich plate between the cover and vessel shell, it is preferable to install monitor elements on the plate at the rear of the vessel. The sandwich plate can then be removed completely and the cover hinges altered to suit. In the case of 150 mm (6 in.) nominal diameter elements, there is a choice of using out-to-in or in-to-out models. Those selected will depend on the required flow direction. Where the flow is from out-to-in, a manifold holding five x 50 mm (2 in.) elements may also be used (as above). Separator Manifold 150 mm diameter in-to-out flow filter monitor elements Figure J1: Simple vessel conversion in which 150 mm diameter filter/coalescer elements are directly replaced by filter monitor elements with equivalent in-to-out flow format Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This Jfile is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 104 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Figure J1 shows the simplest form of conversion where 150 mm diameter in-to-out flow monitor elements have directly replaced the 150 mm diameter filter/coalescers which also have an in-to-out flow format. To enable the use of out-to-in flow monitors, they should be mounted at the outlet of the vessel either directly on the separator mounting stools, or on a specific manifold mounted on the separator stools with an increased number of element positions. This applies to either 50 mm (2 in.) diameter elements or 150 mm (6 in.) out-to-in flow elements (see Figures J2 and J3). However, most end opening FWS with a side-by-side coalescer/separator arrangement have a limited number of outlet ports, or utilise a manifold with perhaps one to three separator elements. In this case, accommodating the number and/or length of monitors to achieve the desired flow usually requires mounting 150 mm out-to-in elements in place of the filter/coalescers and reversing the flow through the vessel. Manifold 50 mm diameter out-to-in flow, filter monitor elements Figure J2: Separator stool manifold conversion for 50 mm diameter filter monitor elements Manifold 150 mm diameter out-to-in flow, filter monitor elements Figure J3: Separator stool manifold conversion for 150 mm diameter out-to-in filter monitor elements Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex J the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 105 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Vessels with a large basket-type separator element can also be modified with a new manifold installed on the outlet position (see Figures J4 and J5). Figure J4: FWS vessel with large basket-type separator before conversion 50 mm diameter out-to-in flow filter monitor elements Figure J5: Vessel in Figure J4 showing outlet manifold conversion for 50 mm diameter filter monitor elements Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This Jfile is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 106 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex J the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 107 Annex K Low point sampling/draining Although this publication focuses on the application of components in the aviation fuel handling system, it should be recognised that manual low point sampling and draining procedures are also vital to the maintenance of fuel cleanliness. For example, the removal of low levels (parts per million) of water by a FWS is a normal operating mode. Over time, the level of coalesced water in the sump of a FWS will rise and there will be a need to drain the water. This is normal operation. If the water is not drained from the sumps of vessels, and low points of tanks and pipelines, then large amounts of bulk water (“slugs”), can find their way into the handling system. Because FWS may become disarmed by contaminants or naturally occurring surfactants, it should not be assumed that they remove all free water. It is recommended that an independent system, such as visual inspection of sump drains, be used with fuel receipts to ensure that particulate matter and free water contamination is controlled. Similarly it should not be assumed that filter monitor elements will remove all free water from fuel. Filter monitor vessel sumps should therefore be checked and drained daily when the system is in use/ pressurised. Three recently developed direct on-site tests for microbes in fuel are available: FUELSTAT, Hylite Jet A1 Fuel Test and MicrobMonitor2. A final point to highlight is that stagnant water bottoms in any fuel system can harbour microbiological growths leading to fuel contamination and tank corrosion. For this reason airport fuel storage should be managed with a regular programme of water bottom removal to deprive microbes of conditions needed for growth. Water drains should be inspected for signs of microbiological contamination (foul sulfurous odours and debris) to identify a problem before it becomes disruptive. There is also operator’s experience of free water contamination of fuel in a refueller being caused by blockage of drainage channels on the top of the tank. This may be caused by leaves, snow, ice and other debris. Pooled water over the recessed manlid may seep into tanks through any minor defects in manlid seals. It is therefore recommended that checks be made after heavy rain, or when the vehicle has been washed, to confirm that water has not entered the tank. Table K1: Recommended low point sampling/draining Low point sampling of: • Storage tanks • Filter vessels (including strainers) • Hydrants • Into-plane fuelling equipment Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This K file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 108 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex K the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 109 Annex L Electrical resistance measurement procedure for filter vessels EI specifications require all metal items inside the vessel (and elements) to be in electrical contact with each other and the vessel and its supporting chassis/frame. The resistance between any two items must be less than 10 ohms. Introduction This annex provides a procedure for performing electrical resistance measurements to identify the presence of any isolated internal components (unbonded charge collectors) in a filter vessel. The procedure indicates a general approach, but each vessel should be treated on an individual basis because of the differences in designs and materials used. The procedure addresses only resistance measurements within the vessel; other earthing and conductivity checks required for the vessel when installed on a vehicle should also be undertaken. Further information on these should be sought from equipment suppliers. The key requirement in avoiding the presence of unbonded charge collectors is to ensure that there is electrical continuity between all metal components within a vessel. It is intended that this procedure will be performed only by personnel who are competent and trained to undertake such tasks. It is recommended that this procedure is performed by the vessel manufacturer, and for mobile applications, the manufacturer of the vehicle upon which the vessel is mounted. Safety considerations If the ambient temperature is near or above the flash point of fuel then the test procedure should NOT be performed unless fuel residue/vapour is entirely absent or a meter is used that is certified safe to use in a hazardous area. The method assumes: If filter monitor elements are removed from a vessel to conduct this test (with the intention to reinstall them), it is important that they are kept in a fuel-wetted condition by placing in a container of clean dry fuel. If elements are allowed to dry, they should be discarded. • That all the relevant safety precautions that are normally taken during routine maintenance are observed. • Normal safety precautions will be observed when using electrical equipment including work permits. • The correct personal protective equipment is used. • The vessel is drained of fuel, and if possible the vessel is allowed to vent to release any hydrocarbon vapours. Equipment required The following equipment is needed for this procedure: Meter: It is preferable to use an insulation tester (500 V minimum, e.g. megger) reading to at least 10 M. The high probe voltage of a megger helps to reduce interference from hydrocarbon films and oxide surface coatings. However, any continuity tester capable of measuring 10 M resistance will give an acceptable indication of electrical continuity if used with adequate care and persistence. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This L file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 110 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Reference connection: A reference connection is an electrically continuous connection from one terminal of the meter to an earth reference point. It is recommended to use one of the vessel support feet as the reference point. The connection to the reference point should be bolted or made via a secure clamp. Test probe: The test probe should consist of a strong, sharp point mounted on a long pole that can reach inside the vessel (Figure L2). The test probe should be connected to the other terminal of the meter by an insulated cable. The pole and cable should be long enough to allow free access to all points inside the vessel. Issues to consider prior to measurement • Electrical continuity needs to be established at the reference point. Paint and coatings may need to be removed to achieve this. • A good contact to each tested component is essential. In some cases paint/epoxy coatings may need to be removed. In the case of aluminium vessels careful consideration will need to be given where metal bushes (bushings) are installed, or if oxides have formed (although the probe will probably be able to pierce the oxide layer with firm pressure and the 500 V+ test equipment will break down thin oxide coatings). • Care is required to ensure that the disassembly process does not isolate any well-bonded items before they can be measured (i.e. test each item before any objects that might provide a bonding link are removed). • The list of items to be tested should include large fixing bolts and threaded rods. It may not be necessary to test small fixing bolts. Testing procedure (based on a filter monitor vessel) Perform steps 1 to 7 (see Figure L1 for explanation of any of the following terms): 1)Attach the reference point connection to a suitable location, such as one of the vessel support feet. Connect the reference point and the probe to the meter. 2)Before opening the lid/end cover check the resistance to the outside of the lid/end cover. 3) Open the lid/end cover and check the resistance to the: A. Pressure plate/interlock or spider (if fitted). B.Any detachable components on the pressure plate or spider (measure these individually). 4) Remove pressure plate/interlock or spider and check the resistance to: A. Each screw rod or other mounting plate fitting (unless welded to case), B. The inlet fuel deflector if fitted and accessible (defer until later if not accessible), and C. 5) The support plate (when in position if removeable). Remove elements and support plate if appropriate and check the resistance to: A. The manifold plate, and B. The check valves or inserts in manifold plate (individually). 6) Check the resistance to the inlet fuel deflector, if previously inaccessible, and any other features not previously checked. 7) If no unbonded charge collectors are found then reassemble the vessel, checking the resistance of metal pieces as they are reinstalled. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex L the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 111 Handbook on equipment used for the maintenance and delivery of clean aviation fuel pressure plate / interlock manifold plate check valves or inserts screw rod / mounting plate fitting lid / end cover *suitable earth reference point support plate vessel support feet inlet fuel deflector Figure L1: A typical vessel Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This L file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 112 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 4O METER )NSULATED COPPER WIRE 3TEEL TIP 4APED HANDLE 7OOD 4IE WRAPS .OTE 0ROBE TO BE SUFFICIENT LENGTH TO REACH INTO VESSEL Figure L2: Test probe Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex L the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 113 Annex M Concept of aviation fuel regulation The following is a generic description of regulation of aviation fuel used for commercial service. Commercial aviation activities are regulated in most countries by Government Agencies and Federal Authorities that oversee aviation hardware, maintenance, and operation. Such oversight typically focuses on manufacturers with respect to the design and construction of aircraft and operators (airlines) for maintenance and operation procedures. Note 17: The major international aviation fuel specifications for jet A/A-1 jet fuel are ASTM D 1655, Def. Stan. 91-91 and Joint Inspection Group AFQRJOS Aviation fuel quality requirements for jointly operated systems (Free to download from: www. jointinspectiongroup.org), (referred to as ‘jet A-1 to checklist’ or ‘checklist jet A-1’). In regulatory terms aviation fuel generally is considered a disposable item regulated quite differently than aviation hardware. For example, while the US Federal Aviation Administration (FAA) does not directly control aviation fuel specifications, quality or cleanliness, it does require an aircraft manufacturer to state which of the available industry specification fuels17 are appropriate for use in a given aircraft model and provide data demonstrating that the aircraft can operate safely on those fuels. When the FAA accepts these data the aircraft is said to be certified for operation on those specified fuels which are listed by the manufacturer in the aircraft operating manual. FAA regulations do not permit the use of other fuels in commercial service. Operators are responsible for observing these limitations in the use of the aircraft. (Note that the above description of the typical situation does not necessarily cover the application of “Supplemental Type Certificates”.) As described in chapter 3, fuel cleanliness is not well defined by aviation industry fuel specifications, even though it is important in aviation operations, because usually cleanliness directly results from fuel handling practices, not from intrinsic fuel properties at the point of production. Normally operators declare their fuel handling procedures, which are then accepted by the appropriate regulatory agency as required procedures and become subject to regulatory oversight. Both ATA (Air Transport Association of America) and IATA airline trade associations write, or endorse, fuel handling guidelines that are usually incorporated into operator procedures by reference. For example, an operator in the US usually states in his contract with the fuel supplier that he handles fuel according to ATA 103. This causes compliance with ATA 103 guidance procedures to be mandatory, subject to FAA audit, for the operator. Aviation fuel handling procedures upstream of the aviation operator usually are not directly subject to regulatory oversight; however, most entities handling aviation fuel have a well defined set of procedures. The most important of these are the JIG (Joint Inspection Group) Guidelines commonly used where three or more suppliers operate in partnership and endorsed by IATA. (However, the JIG Guidelines are usually not used in the US.) The application of an agreed set of handling procedures is usually mandated by the supply contract between the aviation operator and its supplier. Other common aviation fuel handling guidelines include ATA 103 and specific supplier procedures. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This M file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 114 Annex the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex M the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 115 Annex N Definitions The following definitions apply in this publication: Aviation fuel handling system The infrastructure required to safely distribute aviation fuel from its point of manufacture to its point of use. Can be sub-divided into ‘manufacture’, ‘distribution’ and ‘supply’. Batch After production at a refinery, aviation fuel is required to be analysed and certified. This process has to be undertaken on the quantity of fuel contained in a single storage tank, rather than continuously, so once analysed and certified as aviation fuel, that material is described as a batch. Cartridge See element. Commercial The supply of aviation fuel to a company that typically operates a fleet of aircraft for the transport of paying passengers or freight, such as major international airlines. Components used for fuel cleanliness control Any type of filter or electronic sensor. Corrected differential pressure The measured pressure across the vessel at the measured flow rate, after correcting the rated flow of the vessel. Deep-bed filtration A filter with multiple layers of fibres (three-dimensional). Dirt defence filter element An element designed for the removal of only low levels of particulate matter. Dirt defence filter system A vessel containing a number of dirt defence filter elements. Electronic sensor An automated device for the detection of particulate matter and/or free water. Element Term used to describe the ‘disposable’ part of a filter (for either a filter monitor, filter/ coalescer, separator, microfilter or dirt defence filter). Also referred to as a cartridge. Filter/coalescer element An element that contains a porous media through which fuel is passed to remove free water by causing very small droplets of water to form larger drops (coalesce) which separate from fuel by gravity. Typically made from fibre-glass. Coalescers also contain pleated filter media for the removal of fine particulate matter. Filter monitor element An element that contains water-absorbent media (super-absorbent polymer) that removes small amounts of free water from fuel, and is designed to restrict the flow of fuel through it if it is exposed to bulk water. Also has limited particulate matter removal capacity. Filter monitor system A vessel containing a number of filter monitor elements. Filter/water separator A vessel that contains filter/coalescer elements to remove solid particulate matter and to coalesce fine dispersed water droplets, and separator elements to prevent coalesced water droplets from passing downstream of the vessel. Free water from the fuel collects in the sump of the vessel from where it must be periodically drained. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This N file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 116 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Free water Any water in fuel that is not dissolved. Can occur as finely dispersed droplets or in larger quantities as bulk water. Full-scale test A laboratory qualification test of a vessel containing multiple elements at a flow rate representative of that experienced in service. In-to-out Description of the direction of fuel flow across a filter element. The only filter elements designed for in-to-out flow are filter/coalescers and 150 mm (6 in.) nominal diameter filter monitor elements. Into-plane Term used by fuel handling companies to describe the point of delivery of fuel to an aircraft. Also sometimes referred to as into-wing. Into-wing See into-plane. IP Acronym of the former Institute of Petroleum, a UK-based oil industry research institute that merged with the former Institute of Energy to become the Energy Institute in 2003. IP branding of aviation fuel handling publications was retained until 2007. The Energy Institute continues to publish IP test methods. Microfilter element Elements, typically of a pleated paper design, that have a very high particulate matter holding capacity, and are rated to remove a nominal minimum particle size (in microns). Microfilter system A vessel equipped with microfilter elements. Typically applied for the gross removal of particulate matter to protect more sophisticated (and expensive), filter/water separators. Note: Microfilters have no water removal capability. Also referred to as a ’prefilter’, a ‘micronic filter’, or as ‘pre-filtration’. Out-to-in Description of the direction of fuel flow across a filter element. Filter elements that are designed for out-to-in flow are 50 mm (2 in.) and 150 mm (6 in.) nominal diameter filter monitor elements, microfilter elements, dirt defence filter elements and separators used in filter/water separators. Particulate matter Solid material found in fuel, typically mostly rust and silica. Rated flow The flow per inch of length of an element below which the limits of EI specifications can be met. Separator A simple water-repelling (hydrophobic) screen (element), that prevents water droplets from passing downstream of the vessel. Single-element test A laboratory qualification test of one filter element, or in the case of a filter/water separator, a combination of one filter/coalescer and one separator. Three-stage filtration A vessel containing filter coalescers and separators, with filter monitor elements located inside separators. Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex N the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 117 Annex O Bibliography The following are referred to in this publication: API API 1595 Design, construction, operation, maintenance, and inspection of aviation pre-airfield storage terminals ASTM International ASTM D 1141 Standard practice for the preparation of substitute ocean water ASTM D 1655 Standard specification for aviation turbine fuels ASTM D 2276 Test method for particulate contaminant in aviation fuel by line sampling ASTM D 3240 Standard test method for undissolved water in aviation turbine fuels ASTM D 3948 Standard test method for determining water separation characteristics of aviation turbine fuels by portable separometer ASTM D 4176 Standard test method for free water and particulate contamination in distillate fuels (visual inspection procedures) ASTM D 5452 Standard test method for particulate contamination in aviation fuels by laboratory filtration ASTM D 6469 Standard guide for microbial contamination in fuel and fuel systems ASTM E 128 Standard test method for maximum pore diameter and permeability of rigid porous filters in laboratory use ASTM Manual 47 Fuel and fuel system microbiology: Fundamentals, diagnosis, and contamination control Air Transport Association of America, Inc. (ATA) ATA Spec. 103 Standards for jet fuel quality control at airports Canadian General Safety Board 3.23-2005 Aviation turbine fuel (Grades JET A and JET A-1) Coordinating Research Council (CRC) The Handbook of Aviation Fuel Properties (CRC Report No. 635) EI EI 1550 Handbook on equipment used for the maintenance and delivery of clean aviation fuel EI Specification 1581 Specifications and qualification procedures for aviation jet fuel filter/ separators EI 1582 Specification for similarity for EI 1581 aviation jet fuel filter/separators EI Draft Standard 1583 Laboratory tests and minimum performance levels for aviation fuel filter monitors EI Specification 1590 Specifications and qualification procedures for aviation fuel microfilters EI Specification 1596 Design and construction of aviation fuel filter vessels EI Draft Standard 1598 Considerations for electronic sensors to monitor free water and/or particulate matter in aviation fuel EI Specification 1599 Laboratory tests and minimum performance levels for aviation fuel dirt defence filters Guidelines for the investigation of the microbial content of petroleum fuels and for the implementation of avoidance and remedial strategies IP 216 Determination of particulate contaminant of aviation turbine fuels by line sampling IP 423 Determination of particulate contaminant in aviation turbine fuels by laboratory filtration Research Report: Aviation fuel handling: The performance of filter monitors in fuel containing FSII Research Report: Electrostatic discharges in two-inch fuel filter monitors Research Report: Electrostatic discharges in two-inch aviation fuel filter monitors. Phase 2: Properties needed to control discharges Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This O file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex 118 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Research Report: Investigation into the water holding performance of aviation filter monitors with absorbent-type elements, intended for military applications Research Report: The effects of shear and fuel chemistry on the particle size distribution of Fischer I-116 and Elementis R9998 red iron oxides and ISO Ultrafine silica test dusts in jet fuels IATA Guidance material for aviation turbine fuel specifications Guidance material on microbiological contamination in aircraft fuel tanks Innospec Environmental Ltd Leaded gasoline tank cleaning and disposal of sludge International Association for Stability, Handling and Use of Liquid Fuels (IASH) Proceedings of the 7th International Conference on stability, handling and use of liquid fuels ISO ISO 9001 Quality management systems - requirements ISO 12103-1 Road vehicles - Test dust for filter evaluation - Arizona test dust Joint Inspection Group (JIG) JIG 1 Guidelines for aviation fuel quality control and operating procedures for joint into-plane fuelling services JIG 2 Guidelines for aviation fuel quality control and operating procedures for joint airport depots JIG 3 Guidelines for aviation fuel quality control and operating procedures for jointly operated supply and distribution facilities Aviation fuel quality requirements for jointly operated systems (AFQRJOS) Journals L.Z. Pillon, 2001. Surface active properties of clay-treated jet fuels, Petroleum Science & Technology 19: 9-10, pp 1109-1118. Military Specifications (US) MIL-DTL-5624T Turbine fuel, aviation, grades JP-4, JP-5, and JP-5/JP-8 ST MIL-DTL-83133E Turbine fuels, aviation, kerosene types, NATO F-34 (JP-8), NATO F-35, and JP-8+100 MIL-F-5504A/MIL-F-5504B Filters and filter elements, fluid pressure, hydraulic micronic type Ministry of Defence (UK) Defence Defence Standard 91-91 Turbine fuel, Aviation kerosine type, Jet A-1, NATO Code F-35, Joint service designation: AVTUR SAE International Aerospace Standard AS 6401 Storage, handling and distribution of aviation fuels at airfields (provisional title) Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with Annex O the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 119 Handbook on equipment used for the maintenance and delivery of clean aviation fuel Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with 120 the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 Global aviation fuel handling publications The Energy Institute is the provider of the following portfolio of equipment standards and operational recommended practices to facilitate the safe and efficient handling of aviation fuel, particularly at airports. They are available for use internationally. The titles include those that were developed jointly with the API. These are available through the EI from either www.energypublishing.org or Portland Customer Services (t: +44 (0)1206 796 351). The two API titles can be obtained from www.global.ihs.com. For further information on the EI aviation fuel handling portfolio please contact [email protected]. General Title Ed. ISBN EI 1540 Design, construction, operation and maintenance of aviation fuelling facilities 4th 978 0 85293 565 1 EI 1541 Performance requirements for protective coating systems used in aviation fuel storage tanks and piping 1st 978 0 85293 566 8 EI 1542 Identification markings for dedicated aviation fuel manufacturing and 8th distribution facilities, airport storage and mobile fuelling equipment 978 0 85293 567 5 EI 1585 Guidance in the cleaning of aviation fuel hydrant systems at airports 2nd 978 0 85293 568 2 EI 1594 Initial pressure strength testing of airport fuel hydrant systems with water 2nd 978 0 85293 569 9 EI 1597 Procedures for overwing fuelling to ensure delivery of the correct fuel grade to an aircraft 1st 978 0 85293 570 5 EI HM 20 Meter proving: Aviation fuelling positive displacement meters 1st 978 0 85293 302 2 Equipment (excluding filtration) EI 1529 Aviation fuelling hose and hose assemblies 6th 978 0 85293 571 2 EI 1584 Four-inch hydrant system components and arrangements 3th 978 0 85293 572 9 EI 1598 Considerations for electronic sensors to monitor free water and/or particulate matter in aviation fuel 1st 978 0 85293 573 6 EI Research report Review of methods of bonding a hydrant dispenser (servicer) to an aircraft for refuelling 1st 978 0 85293 475 3 Filtration equipment EI 1550 Handbook on equipment used for the maintenance and delivery of clean aviation fuel 1st 978 0 85293 574 3 EI 1581 Specification and qualification procedures for aviation jet fuel filter/separators 5th 978 0 85293 575 0 EI 1582 Specification for similarity for EI 1581 aviation jet fuel filter/separators 1st 978 0 85293 576 7 EI 1583 Laboratory tests and minimum performance levels for aviation fuel filter monitors 5th 978 0 85293 527 9 EI 1590 Specifications and qualification procedures for aviation fuel microfilters 2nd 978 0 85293 577 4 EI 1596 Design and construction of aviation fuel filter vessels 1st 978 0 85293 578 1 EI 1599 Laboratory tests and minimum performance levels for aviation fuel dirt defence filters 1st 978 0 85293 579 8 EI Research report Electrostatic discharges in 2-inch fuel filter monitors 1st 978 0 85293 388 6 EI Research report Electrostatic discharges in 2-inch aviation fuel filter monitors Phase 2: Properties needed to control discharges 1st 978 0 85293 408 1 EI Research report Investigation into the effects of lubricity additives on the performance 1st of filter/water separators 978 0 85293 395 4 North American fuel handling API 1543 Documentation, monitoring and laboratory testing of aviation fuel during shipment from refinery to airport 1st A154301 API 1595 Design, construction, operation, maintenance, and inspection of avia- 1st tion pre-airfield storage terminals A159501 Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 EI Aviation fuel handling publications Aviation fuel filtration EI 1581 Specifications and qualification procedures for aviation jet fuel filter/separators Provides qualification test procedures for filter/water separators. 5th ed Jul 2002 ISBN 978–0–85293–371–8 EI 1582 Specification for similarity for EI 1581 aviation jet fuel filter/separators Provides details of how filter/separators can be qualified by similarity. 1st ed Feb 2001 ISBN 978–0–85293–282–7 EI 1583 Laboratory tests and minimum performance levels for aviation fuel filter monitors Provides minimum recommendations for: selected aspects of filter monitor system and element performance; the general mechanical specifications for new filter monitor elements; laboratory tests and minimum performance requirements for the qualification of new filter monitor elements, and requalification and similarity requirements. 5th ed Nov 2006 ISBN 978–0–85293–473–9 EI 1590 Specifications and qualification procedures for aviation fuel microfilters Provides qualification test procedures for microfilter elements of the disposable cartridge type. 2nd ed Apr 2002 ISBN 978–0–85293–330–5 EI 1596 Design and construction of aviation fuel filter vessels Provides requirements for the design and construction of filter vessels and vessel accessories for filter monitor, filter/water separator and microfilter vessels. 1st ed Nov 2006 ISBN 978–0–85293–428–9 EI 1598 Considerations for electronic sensors to monitor free water and/or particulate matter in aviation fuel Provides minimum design and functional requirements for electronic sensors for the detection of particulate matter and/or free water in aviation fuel handling systems. 1st ed Jul 2007 ISBN: 978–0–85293–483–8 EI 1599 Laboratory tests and minimum performance levels for aviation fuel dirt defence filters Provides minimum recommendations for the general mechanical specifications for dirt defence filter elements, selected laboratory tests and minimum performance requirements for the qualification of new dirt defence filter element designs, requalification and similarity requirements. 1st ed Mar 2007 ISBN 978–0–85293–476–0 EI Research Report: Electrostatic discharges in two-inch fuel filter monitors Documents an investigation commissioned by the Aviation Committee into electrostatic discharge in 50 mm (two inch) nominal diameter aviation fuel filter monitors. Oct 2002 ISBN 978–0–85293–388–6 EI Research Report: Electrostatic discharges in two inch aviation fuel filter monitors. Phase 2: Properties needed to control discharges Documents a theoretical and laboratory based investigation to develop recommendations for the resistance characteristics of 50mm aviation fuel filter monitors to dissipate electrostatic charge safely. Feb 2004 ISBN 978–0–85293–408–1 EI Research Report: Investigation into the effects of lubricity additives on the performance of filter/water separators Documents an investigation into the effects of diesel fuel lubricity additives on the performance of aviation fuel filter/water separators that meet the requirements of API/EI Specification 1581. March 2003 ISBN 978–0–85293–395–4 General fuel handling EI 1529 Aviation fuelling hose and hose assemblies Provides performance specifications and tests required to be carried out by manufacturers. 6th ed May 2005 ISBN 978–0–85293–442–4 EI 1540 Design, construction, operation and maintenance of aviation fuelling facilities Provides guidance on safe practice in the siting, layout, design, construction and operation of aircraft fuelling facilities and associated equipment at airports and airfields. 4th ed Feb 2004 ISBN 978–0–85293–414–2 EI 1542 Identification markings for dedicated aviation fuel manufacturing and distribution facilities, airport storage and mobile fuelling equipment Provides a system for marking aviation fuel types and grades on fuel handling installations and equipment at airports. 8th ed Aug 2007 ISBN 978–0–85293–485–2 EI 1585 Guidance in the cleaning of airport hydrant systems Provides guidance in the cleaning of existing hydrant systems that have become contaminated with water, particulate material or microbiological growth. 1st ed Feb 2001 ISBN 978–0–85293–322–0 EI 1594 Initial pressure strength testing of airport fuel hydrant systems with water Provides guidance for initial pressure strength testing, using water as the test liquid, of new fuel hydrant systems. 1st ed Nov 2002 ISBN 978–0–85293–375–6 EI 1597 Procedures for overwing fuelling to ensure delivery of the correct fuel grade to an aircraft Provides a comprehensive misfuelling prevention program. 1st ed Dec 2006 ISBN 978–0–85293–472–2 EI 1584 Four–inch hydrant system components and arrangements Provides recommended minimum performance and mechanical specifications for the standardization of the design of aviation fuel hydrant system pit valves and associated couplers. 3rd ed Apr 2001 ISBN 978–0–85293–280–3 To order these titles via the EI, visit www.energyinstpubs.org.uk or contact Portland Customer Services t: +44 (0)1206 796 351 Issued under license to Phillips 66 aviation customers only. Not for further circulation. e:rights [email protected] IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100 ISBN 978-0-85293-574-3 To find out more about the work of the Energy Institute, visit www.energyinst.org.uk 61 New Cavendish Street London W1G 7AR, UK t: +44 (0)20 7467 7100 For details of any updates to EI 1550 visit www.energyinst.org.uk/filtration Issued under license to Phillips 66 aviation customers only. Not for further circulation. IMPORTANT: This file is subject to a licence agreement issued by the Energy Institute, London, UK. All rights reserved. It may only be used in accordance with the licence terms and conditions. It must not be forwarded to, or stored or accessed by, any unauthorised user. Enquiries: e: [email protected] t: +44 (0)207 467 7100