NDT Inspection Sheets for Steel Storage Tanks (EEMUA 159)

NDT inspection sheets for above ground
vertical, cylindrical steel storage tanks
Suggested inspection sheets for the inspection of storage tanks.
From EEMUA 159: Above ground flat bottomed storage tanks.
Guide to inspection, maintenance and repair
EEMUA 159 primarily addresses storage tanks built in accordance with relevant British Standards but where
appropriate it also refers to and makes use of commonly accepted international Standards and Codes, such
as those of the American Petroleum Institute (API). These differ little in the in-service conditions that they
cover and the resulting inspection requirements. Accordingly, EEMUA 159 is intended as a general
inspection, maintenance and repair guide applicable to above ground vertical cylindrical steel storage tanks
built to standards such as BS 2654, API 620 and API 650, DIN 4119-1 and -2, CODRES, G0801 and EN
14015.
Below is a minimum of suggested NDT inspection sheets for the elements of steel storage tanks. Use of
these inspection sheets is at the risk of the user and EEMUA takes no responsibility for errors or omissions
that may be found.
This document, used within the context of EEMUA 159, will help ensure that storage tanks are suitably
inspected. Attached are the following inspection sheets.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Bottom Lay-out
Visual Inspection Tank Bottom
Floorscan Indications
Ultrasonic Inspection Tank bottom
Inspection Foundation Shoulder
Planar Tilt Measurement with use of Laser Level tool - 1
Planar Tilt Measurement with use of Laser Level tool - 2
Circumferential Settlement
Edge Settlement Measurements
Uneven Circumferential Settlement
Bottom Sag Measurements with use of Laser Level Tool
Ultrasonic Thickness Measurements of Patch Plates Welded on Bottom Plates
Ultrasonic Thickness Measurements - Bottom Sump(s)
Ultrasonic Thickness Measurements - Tank Shell
Ultrasonic Inspection - Tank Roof (Fixed)
Ultrasonic Inspection - Tank Roof (Single Deck Floating Roof)
Ultrasonic Inspection - Pontoons (Single Deck Floating Roof)
Ultrasonic Inspection - Tank Roof (Double Deck Floating Roof)
Ultrasonic Inspection - Pontoons (Double Deck Floating Roof)
Ultrasonic Inspection - Legs and Leg Sleeves Floating Roofs
Ultrasonic Inspection - Internal Pipeline Systems
Ultrasonic Inspection - External Pipeline Systems
Shell and Roof Nozzles
Ultrasonic Thickness Inspection - Columns
Ultrasonic Thickness Inspection - Roof Columns
Visual Inspection - Tank Bottom (Ripples and Bulges)
Visual and Ultrasonic Inspections - Outside Edge of Bottom
Visual Inspection - Internal Corner Weld Bottom-Shell Connection
Copyright © EEMUA 2018 The Engineering Equipment and Materials Users Association
A company limited by guarantee and registered in England. Company number 477838.
Registered address: EEMUA, Second Floor, 16 Black Friars Lane, London EC4V 6EB
EEMUA 159 and over 70 other EEMUA publications can be bought online from the EEMUA Shop, or by emailing [email protected] or phoning +44 (0) 207 488 0801.
Engineering Equipment and Materials Users Association (EEMUA)
EEMUA aims to improve the safety, environmental and operating performance of industrial facilities in the
most cost-effective way, pursuing and promoting leadership and good practice in industrial asset
management by sharing engineering experiences and expertise. EEMUA guidance is used worldwide
across a variety of industrial and engineering settings.
For more information about EEMUA visit www.eemua.org.
Copyright © EEMUA 2018 The Engineering Equipment and Materials Users Association
A company limited by guarantee and registered in England. Company number 477838.
Registered address: EEMUA, Second Floor, 16 Black Friars Lane, London EC4V 6EB
Bottom Lay-out
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
Class:
Date of examination:
Report number:
Name of inspector:
mm
mm
Schematic lay-out bottom plates + numbering of plates
Manhole North
EXAMPLE
Manhole South
Visual Inspection
Tank Bottom
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
mm
mm
Class:
Inspection date:
Report number:
Name of inspector:
For plate numbers see 'Bottom Lay-out'. Please indicate visually found pits also on 'Bottom Lay-out'
Number of location
Min
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Deepest pit
> 3.5 mm
3.1 - 3.5 mm
2.6 - 3.0 mm
2.0 - 2.5 mm
1.6 - 1.9 mm
1.0 - 1.5 mm
Plate No.
Pit Corrosion
=
0
x deepest pit
Corrosion in
Crevice
welds
Corrosion
Max
Average
Other
Remarks
Pitting from 2.0 mm and deeper: Mark on bottom
Dirty/wet
0
Copper inclusions
0
Tack welds
0
Length [m]
0
Type I/II
0
Length [m]
0
Type I/II
0
Type I: Present
Type II: Requires additional investigation + make note
Floorscan
Indications
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
mm
mm
Class:
Inspection date:
Report number:
Name of inspector:
Thickness from
UT [mm]
Floorscan value
Y-Coordinate
[cm]
X-Co-ordinate
[cm]
Plate number
Thickness from
UT [mm]
Floorscan value
Y-Coordinate
[cm]
X-Co-ordinate
[cm]
Plate number
Report indications of floorscan. Plate number, X-Y co-ordinates, floorscan value, UT value
Ultrasonic Inspection
Tank Bottom
Location:
Tank No.:
Type:
Diameter:
m
Height:
m
Class:
Inspection date:
Report number:
Name of inspector:
tnom Membrane:
mm
tnom Annular:
mm
Membrane plates
1
Annular plates
Scan lines
4
3
5
1
2
Per measuring point: report minimum measured value
1
2
3
4
5
Comments
See Chapter 5.3.5 for further information
1
24
2
25
3
26
4
27
5
28
6
29
7
30
8
31
9
32
10
33
11
34
12
35
13
36
14
37
15
38
16
39
17
40
18
41
19
42
20
43
21
44
22
45
23
46
M/A plate?
M/A plate?
Plate No.
Include in the UT measurement scope - All zones
found by the floor scan technique which are marked
by the operator of the MFL equipment.
Annular plates: Perform UT inspections at the areas
3, 4 and 5 covering zones of 500mm long and
250mm wide. Perform UT inspections at the areas 1
and 2 covering zones of 250mm long and 250mm
wide. Record the least minimum thickness found at
these locations. When excessive thickness losses (by
pitting corrosion) are found extend the areas 3, 4 and
5 by performing UT measurements to 100% of the
circumferential length over an inwards zone of
250mm.
Plate No.
Membrane plates: UT thickness measurements on
grid line system according to Table 5-3, Section 5.3.4
(connect the points at the shell to each other and
measure along the these lines at the following points
(see Section 5.3.5): 25mm inwards of the tank shell;
300mm inwards of the tank shell; 750mm inwards of
the tank shell and further at distances not in excess
of 3m from each other.
1
2
3
4
5
Comments
Ultrasonic Inspection
Tank Bottom
Location:
Tank No.:
Type:
Diameter:
m
Height:
m
Class:
Inspection date:
Report number:
Name of inspector:
tnom Membrane:
mm
tnom Annular:
mm
Membrane plates
1
Annular plates
Scan lines
4
3
5
1
2
Per measuring point: report minimum measured value
1
2
3
4
5
Comments
See Chapter 5.3.5 for further information
47
70
48
71
49
72
50
73
51
74
52
75
53
76
54
77
55
78
56
79
57
80
58
81
59
82
60
83
61
84
62
85
63
86
64
87
65
88
66
89
67
90
68
91
69
92
M/A plate?
M/A plate?
Plate No.
Include in the UT measurement scope - All zones
found by the floor scan technique which are marked
by the operator of the MFL equipment.
Annular plates: Perform UT inspections at the areas
3, 4 and 5 covering zones of 500mm long and
250mm wide. Perform UT inspections at the areas 1
and 2 covering zones of 250mm long and 250mm
wide. Record the least minimum thickness found at
these locations. When excessive thickness losses (by
pitting corrosion) are found extend the areas 3, 4 and
5 by performing UT measurements to 100% of the
circumferential length over an inwards zone of
250mm.
Plate No.
Membrane plates: UT thickness measurements on
grid line system according to Table 5-3, Section 5.3.4
(connect the points at the shell to each other and
measure along the these lines at the following points
(see Section 5.3.5): 25mm inwards of the tank shell;
300mm inwards of the tank shell; 750mm inwards of
the tank shell and further at distances not in excess
of 3m from each other.
1
2
3
4
5
Comments
Ultrasonic Inspection
Tank Bottom
Location:
Tank No.:
Type:
Diameter:
m
Height:
m
Class:
Inspection date:
Report number:
Name of inspector:
tnom Membrane:
mm
tnom Annular:
mm
Membrane plates
1
Annular plates
Scan lines
4
3
5
1
2
Per measuring point: report minimum measured value
1
2
3
4
5
Comments
See Chapter 5.3.5 for further information
93
116
94
117
95
118
96
119
97
120
98
121
99
122
100
123
101
124
102
125
103
126
104
127
105
128
106
129
107
130
108
131
109
132
110
133
111
134
112
135
113
136
114
137
115
138
139
144
140
145
141
146
142
147
143
148
M/A plate?
M/A plate?
Plate No.
Include in the UT measurement scope - All zones
found by the floor scan technique which are marked
by the operator of the MFL equipment.
Annular plates: Perform UT inspections at the areas
3, 4 and 5 covering zones of 500mm long and
250mm wide. Perform UT inspections at the areas 1
and 2 covering zones of 250mm long and 250mm
wide. Record the least minimum thickness found at
these locations. When excessive thickness losses (by
pitting corrosion) are found extend the areas 3, 4 and
5 by performing UT measurements to 100% of the
circumferential length over an inwards zone of
250mm.
Plate No.
Membrane plates: UT thickness measurements on
grid line system according to Table 5-3, Section 5.3.4
(connect the points at the shell to each other and
measure along the these lines at the following points
(see Section 5.3.5): 25mm inwards of the tank shell;
300mm inwards of the tank shell; 750mm inwards of
the tank shell and further at distances not in excess
of 3m from each other.
1
2
3
4
5
Comments
Inspection Foundation
Shoulder
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
Pad finish
Class:
Inspection date:
Report number:
Name of inspector:
mm
mm
Leak detection sump
present?
Tiles:
Yes :
Asphalt:
No:
If yes: mark presence of
liquid in sump
Yes
No
Product
Water
Concrete:
Substance found
Mixture product/water
Pad slope is adequate for drainage purpose
Position tank relative to pad
Pad height
Position tank base higher than pad level
Slight settlement
Tank base reached same level as pad top
Tank base is lower than pad top (no
drainage possible)
Note any pad damage
Mark location of manhole
Mark tank North position by means of an arrow
Planar Tilt Measurement
with use of Laser Level
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Planar tilt measurement:
Measurements to be taken on a number of measurement points (to be established by the formula:
N = D/3.05 with a minimum of 8 points and maximum distance of 10m between measuring points).
Locate measuring points starting from spiral stair or liquid level measuring device:
1 position as low as possible at tank base
1 position as high as possible near compression area or top curb angle
See Chapter 6.5.1, Figure 6-14
0 mm
0 mm
The number of
measuring points to be
taken along the
circumference depends
on the diameter of the
tank. Note that only 4
points have been
identified in this sketch
for reason of simplicity.
0 mm
0 mm
Planar Tilt Measurement
with use of Laser Level
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Planar tilt measurement:
Measure verticality of vessel at the location of each column.
Start numbering on North side and count clockwise.
1 position as low as possible at tank shell
1 position as high as possible near top of shell
Mark the difference between the 2 perpendicular points
NORTH
0 mm
0 mm
0 mm
0 mm
SOUTH
Circumferential Settlement
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Level measurement:
Measure level on base plate of each column.
Start numbering on North side and count
clockwise.
NORTH
1
2
3
4
5
6
7
8
Result.
dH [mm]
interval
10m
Correction
Value
Point
mm
Remarks
Edge Settlement
Measurements
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
mm
mm
Class:
Inspection date:
Report number:
Name of inspector:
B
Factor of Edge Settlement (FES)
B
B
FES = H/B
RZFmax = 0.1667
H
H
750 mm
-H
750 mm
750 mm
Measure on number of measuring points (to be established by the formula:
N = D/3.05 with a minimum of 8 points and maximum distance of 10m between measuring points).
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
1
1
1
2
2
2
3
3
3
H
B
FES
Result.
FES
Measurement
No.
B
Plate No.
H
Result.
FES
Measurement
No.
B
Plate No.
H
Result.
Measurement
No.
Plate No.
See Section 6.5.2 for maximum distance of B and required reduction of distance B when deformation in annular shows a
summit at a distance smaller than 750mm inwards of the tank shell.
Uneven Circumferential
Settlement
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
dHmax
6m
36m
max. 300mm
Result.
dH [mm]
interval 10m
Correction
Value
Measurements:
Measure on number of measurement points (to be
established by the formula: N = D/3.05 with a minimum of
8 points and maximum distance of 10m between measuring
points). See Section 6.5.3.
Locate measuring points starting from spiral stair or liquid
level measuring device:
Criteria:
dH between 2 adjacent points: max. 100 mm or 1% of arc
length between measuring points.
dHmax for floating roof tanks equipped with -X/+3X seals:
between Hmax and Hmin according to graph.
dHmax for floating roofs equipped with -X/+X seal should be
established from formula in Chapter 6.5.3.b.
100mm
Point
Inspection date:
Report number:
Name of inspector:
Remarks
Bottom Sag
Measurements with use
of Laser Level Tool
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Number of scan lines:
Number of scanlines according to
formula:
N = D/3.05 with a minimum scan 8
lines and a maximum distance
between scan lines of 10m.
See Chapter 6.5.4
1
Scan lines
Bottom sag measurements:
The required minimum number of scan lines should
be spaced equally over the tank base.
Measure the height over the length of the scan line,
every 2 metres, starting and ending against the
tank shell.
'M' = Level measurement
'C' = Difference in height between highest point per
scan line and point under consideration.
Scan line 1
Scan line 2
Scan line 3
Scan line 4
Scan line 5
Scan line 6
No.
No.
No.
No.
No.
No.
M
C
M
C
M
C
M
C
M
C
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
4
4
4
4
4
4
5
5
5
5
5
5
6
6
6
6
6
6
7
7
7
7
7
7
8
8
8
8
8
8
9
9
9
9
9
9
10
10
10
10
10
10
11
11
11
11
11
11
12
12
12
12
12
12
13
13
13
13
13
13
14
14
14
14
14
14
15
15
15
15
15
15
16
16
16
16
16
16
17
17
17
17
17
17
18
18
18
18
18
18
19
19
19
19
19
19
20
20
20
20
20
20
21
21
21
21
21
21
22
22
22
22
22
22
23
23
23
23
23
23
24
24
24
24
24
24
25
25
25
25
25
25
26
26
26
26
26
26
27
27
27
27
27
27
M
C
Bottom Sag
Measurements with use
of Laser Level Tool
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Number of scan lines:
Number of scanlines according to
formula:
N = D/3.05 with a minimum scan 8
lines and a maximum distance
between scan lines of 10m.
See Chapter 6.5.4
1
Scan lines
Bottom sag measurements:
The required minimum number of scan lines should
be spaced equally over the tank base.
Measure the height over the length of the scan line,
every 2 metres, starting and ending against the
tank shell.
'M' = Level measurement
'C' = Difference in height between highest point per
scan line and point under consideration.
Scan line 7
Scan line 8
Scan line 9
Scan line 10
Scan line 11
Scan line 12
No.
No.
No.
No.
No.
No.
M
C
M
C
M
C
M
C
M
C
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
4
4
4
4
4
4
5
5
5
5
5
5
6
6
6
6
6
6
7
7
7
7
7
7
8
8
8
8
8
8
9
9
9
9
9
9
10
10
10
10
10
10
11
11
11
11
11
11
12
12
12
12
12
12
13
13
13
13
13
13
14
14
14
14
14
14
15
15
15
15
15
15
16
16
16
16
16
16
17
17
17
17
17
17
18
18
18
18
18
18
19
19
19
19
19
19
20
20
20
20
20
20
21
21
21
21
21
21
22
22
22
22
22
22
23
23
23
23
23
23
24
24
24
24
24
24
25
25
25
25
25
25
26
26
26
26
26
26
27
27
27
27
27
27
M
C
Bottom Sag
Measurements with use
of Laser Level Tool
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Number of scan lines:
Number of scanlines according to
formula:
N = D/3.05 with a minimum scan 8
lines and a maximum distance
between scan lines of 10m.
See Chapter 6.5.4
1
Scan lines
Bottom sag measurements:
The required minimum number of scan lines should
be spaced equally over the tank base.
Measure the height over the length of the scan line,
every 2 metres, starting and ending against the
tank shell.
'M' = Level measurement
'C' = Difference in height between highest point per
scan line and point under consideration.
Scan line 13
Scan line 14
Scan line 15
Scan line 16
Scan line 17
Scan line 18
No.
No.
No.
No.
No.
No.
M
C
M
C
M
C
M
C
M
C
M
C
1
1
1
1
1
1
2
2
2
2
2
2
3
3
3
3
3
3
4
4
4
4
4
4
5
5
5
5
5
5
6
6
6
6
6
6
7
7
7
7
7
7
8
8
8
8
8
8
9
9
9
9
9
9
10
10
10
10
10
10
11
11
11
11
11
11
12
12
12
12
12
12
13
13
13
13
13
13
14
14
14
14
14
14
15
15
15
15
15
15
16
16
16
16
16
16
17
17
17
17
17
17
18
18
18
18
18
18
19
19
19
19
19
19
20
20
20
20
20
20
21
21
21
21
21
21
22
22
22
22
22
22
23
23
23
23
23
23
24
24
24
24
24
24
25
25
25
25
25
25
0.0
26
26
26
26
26
26
Min:
27
27
27
27
27
27
0.0
Max:
Ultrasonic Thickness
Measurements of Patch Plates
Welded on Bottom Plates
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
2
1
4
3
Patch plate located on:
'M' = Membrane plate
'A' = Annular plate
5
2
3
4
5
Remarks
1
37
2
38
3
39
4
40
5
41
6
42
7
43
8
44
9
45
10
46
11
47
12
48
13
49
14
50
15
51
16
52
17
53
18
54
19
55
20
56
21
57
22
58
23
59
24
60
25
61
26
62
27
63
28
64
29
65
30
66
31
67
32
68
33
69
34
70
35
71
36
72
M/A plate?
1
Plate No.
M/A plate?
Plate No.
Indicate per measuring point the minimum found thickness per Plate No.
1
2
3
4
5
Remarks
Ultrasonic Thickness
Measurements Bottom
Sump(s)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
tnom Membrane:
tnom Annular:
mm
mm
Class:
Inspection date:
Report number:
Name of inspector:
See Section 5.3.5, Figures 5-9 and 5-10
A to D
Bottom sump
E
Location
A
B
C
D
E
Thickness
A to D
E
A
D
Sump
B
C
Bottom plates
near Sump
A
B
C
D
Min
Ultrasonic Thickness
Measurements Tank
Shell
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
1
Scan lines
Scan line 1
ring 30
⅓h
Class:
Diameter
No of scan lines
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15m interval
Scan line 2
⅔h
ring
Inspection date:
Report number:
Name of inspector:
30
⅓h
Thickness measurements tank shell:
Locate minimum required scan lines equally over
circumference of tanks.
As a minimum: measure plate thickness, per scan line, on
each shell course at 3 locations ⅓h, ⅔h and 30mm above
lowest horizontal weld seam of each course.
OR (preferably)
Use automatic UT crawler and measure each 100mm over
the full shell height per scan line.
Scan line 3
⅔h
ring
30
⅓h
Scan line 4
⅔h
ring
1
1
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
8
8
9
9
9
9
10
10
10
10
11
11
11
11
Scan line 5
ring 30
⅓h
Scan line 6
⅔h
ring
30
⅓h
Scan line 7
⅔h
ring
30
⅓h
ring
1
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
8
8
9
9
9
9
10
10
10
10
11
11
11
11
Scan line 9
⅓h
Scan line 10
⅔h
ring
30
⅓h
Scan line 11
⅔h
ring
30
⅓h
⅓h
⅔h
Scan line 8
⅔h
1
ring 30
30
30
⅓h
⅔h
Scan line 12
⅔h
ring
1
1
1
1
2
2
2
2
3
3
3
3
4
4
4
4
5
5
5
5
6
6
6
6
7
7
7
7
8
8
8
8
9
9
9
9
10
10
10
10
11
11
11
11
30
⅓h
⅔h
Ultrasonic Inspection
Tank Roof (Fixed)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Thickness measurements roof plates:
1
Scan lines
Diameter
No of scan lines
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15m interval
Divide scan lines evenly over tank circumference.
4 measurements per scan line on ⅓R, ⅔R and
200mm away from tank shell + centre plate
(crown plate).
See Chapter 5.3.6.1
R
200
1
11
21
31
2
12
22
32
3
13
23
33
4
14
24
34
5
15
25
35
6
16
26
36
7
17
27
37
8
18
28
38
9
19
29
39
10
20
30
40
200 ⅓R
⅔R
Crown plate
⅔R
Scan line
200 ⅓R
Crown plate
⅔R
Scan line
200 ⅓R
Crown plate
⅔R
Scan line
200 ⅓R
⅔R
Crown plate
Scan line
⅓R
Ultrasonic Inspection
Tank Roof (Single
Deck Floating Roof)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Thickness measurements roof plates:
1
Scan lines
Diameter
No of scan lines
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15m distance
between points
along circumference
Divide scan lines equally over tank
circumference.
3 measurements per scan line on ⅓R,
⅔R and (R- 3m) from centre of roof.
See Section 5.3.6.2
3000
R - 3m
⅔R
1
11
21
31
2
12
22
32
3
13
23
33
4
14
24
34
5
15
25
35
6
16
26
36
7
17
27
37
8
18
28
38
9
19
29
39
10
20
30
40
Sump floating roof
⅓R
⅔R
R - 3m
⅔R
Scan line
⅓R
R - 3m
⅔R
Scan line
⅓R
R - 3m
⅔R
Scan line
⅓R
R - 3m
Scan line
⅓R
B
C
D
A to D
Measurement
E
Plate thickness
A
D
Sump
B
C
Roof plates near
sump
A
B
C
D
A
E
Min
Ultrasonic Inspection
Pontoons (Single Deck
Floating Roof)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Pontoons:
Numbering of pontoons from guide pole.
Measuring point 'E' at height of liquid level.
Measuring point 'A' at 200mm away from outer-rim edge.
Measuring point 'B': 25mm above the connecting weld of the
centre membrane to the inner rim plate of the pontoon.
Measuring points 'C1', 'C2', 'C3', 'C4'; 50mm away from,
respectively the outer or inner rim plates of the pontoons and
50mm away from the bulkhead plates.
Measuring points 'D1', 'D2', and 'D3'; 25mm above the weld of
the lower deck plates of the pontoons.
Guide pole
A
Start
numbering
E
B
D
C
C
Bottom deck pontoon
C1
Point
C2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
Inspection date:
Report number:
Name of inspector:
Outer-rim plate
C3
E1
E2
E3
C4
D1
D2
D3
Inner-rim plate
Top deck pontoon
A
B
Measurement positions
A
B
C1
C2
C3
C4
D1
D2
D3
E1
E2
E3
Ultrasonic Inspection
Tank Roof (Double
Deck Floating Roof)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
1
Scan lines
Thickness measurements Roof plates:
Diameter:
Number of scan lines:
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15m distance
between points along
Divide scan lines equally over tank
circumference.
3 measurements per scan line on ⅓R, ⅔R and
200mm away from outer rimplate edge.
R
200
⅔R
⅓R ⅔R 200
Scan line
Scan line
⅓R ⅔R 200
Scan line
Scan line
⅓R
⅓R ⅔R 200
1
11
21
31
2
12
22
32
3
13
23
33
4
14
24
34
5
15
25
35
6
16
26
36
7
17
27
37
8
18
28
38
9
19
29
39
10
20
30
40
Sump floating roof
⅓R ⅔R 200
A to D
Measurement
E
Plate thickness
A
D
Sump
B
C
Roof plates near
sump
A
B
C
D
A
B
C
D
E
Min
Ultrasonic Inspection
Pontoons (Double Deck
Floating Roof)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Guide pole
D
D
C
C C
D
C
C
Bottom deck plate
C1
C2
Pontoons:
Numbering of pontoons from guide pole.
Measuring points 'A' and 'B' in a double deck
floating roof are to be deleted
Measuring points 'C1', 'C2', 'C3', 'C4'; 50mm
away from, respectively the outer or inner rim
plates of the pontoons and 50mm away from the
bulkhead plates.
Measuring points 'D1', 'D2', and 'D3'; 25mm
above the weld of the lower deck plates of the
pontoons.
Outer rim plate
Bottom deck plate (centre pontoon)
C3
C3
D2
D1
C4
D3
C1
C4
Pont.
C2
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
34
35
36
37
Measuring Positions
C1
C2
C3
C4
D1
D2
D3
Ultrasonic Inspection
Legs and Leg Sleeves
Floating Roofs
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Leg sleeves:
Guide pole
Positions A t/m D
Ring A
Ring B
Ring C Etc.
Measured
max 50 mm
Numbering of all landing legs of floating roof, per ring starting at the
nearest leg right of the guide pole. Inspect each 2nd leg on the
following areas - in total 50% of leg sleeves.
Per leg sleeve:
Scan area at liquid level, over a length of approx. 300mm above centre
deck plate between gusset plate.
Scan area just above each connecting pin at top side of sleeves above
each hole in the sleeves over full remaining length of the sleeve.
See Chapter 5.3.6.2, Figure 5-12
Ring No.
Leg.No.
Scan lines
A
B
C
D
Min.
Remarks:
Ultrasonic Inspection
Internal Pipeline
Systems
A
Loc.1 Loc.2
2m
2m
Loc.n
D
B
C
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
Internal piping systems:
Line identification:
Start numbering of measurement points from tank to centre of
tank.
Measure along length of pipe line each 2 metres on 4 points
Per measurement location record thickness at A to D according
to the figure.
Measurement Position
Elbow
m
m
Inspection date:
Report number:
Name of inspector:
Loc. No.
Diameter:
Height:
Class:
Schedule
Type:
Diameter
Location:
Tank No.:
A
B
C
D
Min.
Ultrasonic Inspection
External Pipeline
Systems
Location:
Tank piping:
A
Loc.n
Loc.2
Loc.1
2m
2m
D
B
C
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
37
Line identification:
Start numbering of measurement points from tank to bund
wall.
Measure along length of pipe line each 2 metres on 4 points
Per measurement location record thickness at A to D according
to the figure.
Measurement position
Elbow
m
m
Inspection date:
Report number:
Name of inspector:
Loc. No.
Diameter:
Height:
Class:
Schedule
Type:
Diameter
Tank No.:
A
B
C
D
Min.
Shell and Roof
Nozzles
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Shell Nozzles
A
4No. UT wall thickness measurements are recommended.
D
B
Schedule
Diameter
Nozzle No.
C
Start numbering nozzles from North/South line of tank. Measure locations at 12 o'clock (Point
A), 3 o'clock (Point B), 6 o'clock (Point C) and 9 o'clock (Point D).
Any nozzle not measured or not accessible or insulated nozzles, please mark as not measured.
Description
A
B
C
D
Min.
Remarks
1
2
3
4
5
6
7
8
9
10
11
12
Roof Nozzles
A
D
4No. UT wall thickness measurements are recommended.
B
C
Start numbering nozzles from North/South line of tank. Measure locations at 12 o'clock (Point
A), 3 o'clock (Point B), 6 o'clock (Point C) and 9 o'clock (Point D).
Any nozzle not measured or not accessible or insulated nozzles, please mark as not
measured.
1
2
3
4
5
6
7
8
9
10
11
12
Schedule
Diameter
Nozzle No.
See Chapter 5.3.7, Figure 5-14.
Description
A
B
C
D
Min.
Remarks
UT Inspection
Columns
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
A
Thickness measurement columns
3 measurement locations divided over height of the column:
(1) at connection to tank;
(2) at 1/2h; and
(3) at 30mm above the base of the column.
D
C
4 measurements shall be taken at 90 degrees at each location (points A to D).
Point
1
CROSS SECTION OF COLUMN
Location
A
B
C
D
X
[mm]
2
[mm]
3
[mm]
B
1
h
2
3
UT Inspection
Roof Columns
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
Measurement (see also Section 10.4)
1
2
3
4
A
5
6
7
8
Survey Thickness Measurement Location
line
A
B
C
D
I
II
III
IV
I
II
III
IV
I
II
III
IV
I
II
III
IV
I
II
III
IV
I
II
III
IV
I
II
III
IV
I
II
III
IV
Min.
Ring Column
Avg.
Each column is to be measured at 4 survey lines (see sketch)
Each survey line has 3 to 4 measurement locations (A to D)
Max. allowable tilt: H/100 with a maximum of 125mm
R is the rotation (twist) of the profile.
Tilt A-C Tilt D-B
Twist
R
Remarks
Visual Inspection
Tank Bottom
(Ripples and Bulges)
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
Class:
Inspection date:
Report number:
Name of inspector:
When, during visual inspections, ripples or bulges are found, the dimensions of these deformations
should be measured.
1)
For ripples (fully supported by foundation materials) see Section 6.5.5:
H/W ration should be > 0.15
2)
For hollow sections see Section 7.5:
60
75
1)
400
500
Example: The maximum allowable height of a ripple with a width of 400mm should be 0.15 x 400 = 60mm
Figure 6-19 Maximum ripple dimensions
No.
Measured height
[mm]
Measured width
[mm]
Ratio
1
2
3
4
5
6
200
2)
Hollow space
Foundation material
3000
Figure 7-8 Bulges not filled with foundation material
No.
1
2
3
4
5
6
Measured height
[mm]
Measured width
[mm]
Ratio
Visual and Ultrasonic
Inspections
Outside Edge of Bottom
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
1
Class:
Scan lines
Inspection date:
Report number:
Name of inspector:
Diameter
No of scan lines
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15 m interval
See Section 7.4.3, Figure 7-3
Measured thickness [mm]
Point
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Location
tmin
LI
Visual Inspection
Internal Corner Weld
Bottom-Shell Connection
Location:
Tank No.:
Type:
Diameter:
Height:
m
m
1
Class:
Scan lines
Inspection date:
Report number:
Name of inspector:
Diameter
No of scan lines
D < 20
4
20 ≤ D ≤ 36
8
D > 36
Max. 15m interval
See Section 7.4.3.1, Figure 7-4
R inside Radius of tank shell
A measured (throat thickness)
Ameasured
Point
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Location
[mm]