Dimensions

Question 1

Definitions- Length of shell-to-bottom weld that if repaired is considered either a major repair or alteration

Answer 1

> 0”

Question 2

Linings- Typically anchor profile of steel surface required for the installation of a tank bottom lining

Answer 2

1.5- 4.0 mils

Question 3

Welds- Maximum undercut of a vertical weld & nozzle weld

Answer 3

1/64”

Question 4

Welds- Maximum undercut of horizontal weld

Answer 4

1/32”

Question 5

Welds- Maximum diameter of a surface porosity cluster

Answer 5

1/32”

Question 6

Weld Qualification- Max allowed discontinuity in a Bend Test

Answer 6

1/8”

Question 7

Nameplates- Minimum size of nameplate letters

Answer 7

5/32”

Question 8

Bottoms- Minimum external projection of bottom plate on an existing tank (from toe of shell-to-bottom FW)

Answer 8

3/8”

Question 9

Reconstruction - Max amount of peaking allowed in vert welds

Answer 9

1/2”

Question 10

Shell Calcs- When calculating tmin for shell LTA, minimum distance away from a weld where “E” is always 1.0

Answer 10

> 1” or 2t

Question 11

Shell Patch- minimum overlap of shell lap-patch used to cover a hole (edge of hole to edge of patch)

Answer 11

1”

Question 12

NDE- When performing a PT examination, minimum distance to clean beyond the area to be examined

Answer 12

1”

Question 13

NDE- When performing a MT examination, minimum distance to clean beyond the area to be examined

Answer 13

1”

Question 14

Reconstruction- Maximum amount of banding allowed in a horizontal weld

Answer 14

1”

Question 15

Bottoms- Minimum overlap required for single-lwelded lap joints

Answer 15

1”

Question 16

Bottoms- Minimum external projection of bottom plate on a new tank

Answer 16

2”

Question 17

Vacuum Box- Minimum overlap of previously tested surfaces when using a vacuum box

Answer 17

2”

Question 18

Bottom Patch- Minimum overlap of bottom lap=patch used to cover corroded area (Edge of corrosion to edge of patch)

Answer 18

2”

Question 19

Bottom Patch- Minimum distance bottom lap=patch fillet weld to the nearest existing bottom weld

Answer 19

2”

Question 20

Shell Patch- Minimum radius of a shell lap-patch

Answer 20

2”

Question 21

Reconstruction- If reusing bottom plates, min distance to cut from existing bottom welds (if plates are not deseamed)

Answer 21

2”

Question 22

Reconstruction- If reusing roof plates, min distance to cut from existing roof welds (if plates are not deseamed)

Answer 22

2”

Question 23

Shell Pitting- Maximum allowed vertical length of pits on a tank shell

Answer 23

2” in 8” line

Question 24

bottom pitting- maximum allowed length of pits in the critical zone that can be repaired by weld-buildup

Answer 24

2” in 8” arc

Question 25

Bottoms- Radial length of critical zone measured from shell

Answer 25

3"

Question 26

Bottoms- Suggested pad thickness

Answer 26

3-4"

Question 27

Welds- Min distance between clusters of surface porosity

Answer 27

4"

Question 28

Shell Patch- Minimum dimension of a shell lap-patch

Answer 28

4"

Question 29

Shell Patch- Minimum radius of a shell flush-patch

Answer 29

6"

Question 30

Shell calcs- When calculating tmin for shell LTA, minimum distance away from a rivet where "E" is always 1.0

Answer 30

6"

Question 31

Bottom Patch- Minimum radius of a shell flush-patch

Answer 31

6"

Question 32

Bottom Patch- Minimum distance between a bottom lap-patch and the shell for patches that do NOT extend to the shell

Answer 32

6"

Question 33

Reconstruction- If reusing shell plates, min distance to cut from existing shell welds (if plates are not deseamed)

Answer 33

6"

Question 34

RT- Minimum diagnostic length of a RT for vertical or horizontal welds

Answer 34

6"

Question 35

Weld Qualification- Minimum length of a RT for vertical or horizontal welds

Answer 35

6"

Question 36

Weld Qualification- Minimum length of RT when qualifying a welding operator with RT of a test coupon

Answer 36

6"

Question 37

Shell Patch- Minimum distance to overlap a shell weld when using a lap-patch

Answer 37

6"

Question 38

Corrosion- Area to dig when checking for soil-to-air corrosion

Answer 38

6-12"

Question 39

Vacuum Box- Typical size of a vacuum box

Answer 39

6" x 30"

Question 40

Shell Patch- Minimum dimension of a shell flush-patch

Answer 40

12"

Question 41

Bottoms- Minimum dimension that a 3-lap joint can be from: other 3-laps, the shell, or annular plate joints

Answer 41

12"

Question 42

Bottom Patch- Minimum dimension of bottom lap-patch that crosses a bottom seam

Answer 42

12"

Question 43

Foundations- Suggested height above grade for new tank bottoms

Answer 43

12"

Question 44

Shell Patch- When adding a shell flush-patch that extends to a horizontal shell weld, minimum distance to cut the horizontal weld past the new vertical welds

Answer 44

12"