Parameters Type Pump and Specification ANSI API ANSI B73. 1 for horizontal end suction top API 610 for horizontal single and multlstage discharge pump. pumps. vertical in-line, vcrtical single, and ANSI 873.2 for vertical In-line pumps. multistage centrifugal pumps. All are single stage. Maximum Allowable Working 275 PSIG Pressure (MAWP) Minimum 700 PSlG Some API pumps are designed for pressure above 500 PSIG. Hydrostatic Test Pressure 415 PSIG Minimum 1050 PSIG API pump hydrostatic test pressure will be 1.5 times the MAWP. Flange Rating 150# flat faced is standard. 150# raised face is available. 300# raised face is standard. 600, 900, 1500 and higher ratings are available if required by the service. Maximum Temperature 2SO°F 800°F Pump casing is foot mounted which limits Pump casing is centerline mounted. No casing allowable thermal growth thermal growth limitations. Materials of Constructions (Casing and Impeller) Ductile Iron 316SS Alloy 20 A carbon steel casing or impeller is not commonly available Carbon steel casing is standard. Stainless steel is also available. Impelller materials are cast iron, carbon steel, and stainless steel. Maximum Head Differential 550 to 600 feet ANSI pumps are only single stage. Maximum impeller diameter is about 13 inches. Practical limit is 10000 feet. Horizontal API pumps can have as many as 14 stages. Impeller Design and Attachment All are enclosed design. Some open designs Open impellers are common. Some are available for special coke crushing enclosed impellers are available. services. No standard for attachment to the shaft. Impellers must be key driven with a lock nut Most are threaded on the end of the shaft. attachment. Standard Dimensions ANSI pumps are built for interchangeability between manufacturers. Shaft Sleves Not required but are available. Fit to the Are required to prevent shaft damage in the shaft and extension past the gland are not scal or packing area. ANSI specification requirements. Sleeve and stuffing box design is part of the No standard dimensions apply. API 610 specification. Lubrication Can be grease or oil lubricated. Oil lubrication is required. Usually ring oil system is provided. Antifriction ball bearings must be duplex, single row, 40-degree angular-contact type, Antifriction bearings only. Thrust bearing and installed back to back. B-10 bearing life of 17500 hours at design Life L-10 bearing life must exceed 25,000 hours at load is required. rated condition, or 16,000 hours at maximum axial and radial loads at rated speed. Wear Rings Not required and not available in most designs due to the use of open impellers. Case and impeller, front and back wear rings are required. Wear ring clearences, attachment and hardness differential are specified. Conclusion : API-compliant pumps are always a better choice than ANSI or ISO pumps
