Thicknesses

Question 1

Linings – Typical thickness of an Inorganic Zinc lining

Answer 1

3-5 mil

652: 6.2.1

Question 2

Linings - Thickness of a thin film lining

Answer 2

< 0.020”

652: 3.29

Question 3

Bottom - Minimum allowed bottom plate thickness when there is a Reinforced Liner that is > 0.050” thick

Answer 3

0.050”

653: Table 4.4

Question 4

Bottom - Minimum allowed bottom plate thickness when there is a means to Detect and Contain a leak

Answer 4

0.050”

653: Table 4.4

Question 5

Roofs - Minimum allowed average thickness of corroded roof plate

Answer 5

0.090” in 100 in^2

653: 4.2.1.2

Question 6

Shell - Minimum arbitrary shell thickness (used when calculated minimum thickness is below this number)

Answer 6

0.100”

653: 4.3.3.1
(tmin note)

Question 7

Bottom - Minimum allowed thickness of bottom plate at toe of the external shell-to-bottom fillet weld

Answer 7

0.100”

653: 4.4.5.7

Question 8

Bottom - Minimum allowed bottom plate thickness away from critical zone or an annular plate

Answer 8

0.100”

653: Table 4.4

Question 9

Bottom - Minimum allowed plate thickness in critical zone that can be repaired by weld-buildup

Answer 9

0.100”

653: 9.11.1.6.b

Question 10

Bottom - Minimum allowed thickness in critical zone

Answer 10

0.118”

653: 4.4.5.4

Question 11

Roof – Min thickness of new steel roof plate (cone & floating)

Answer 11

3/16”

650: 5.10.2.2 & C.3.3.2

Question 12

Roof Rim - Minimum thickness of new roof rim

Answer 12

3/16”

653: 9.14.6.2

Question 13

Bottom - Normal minimum thickness of new bottom plate

Answer 13

1/4” (0.236”)

650: 5.3.5/5.4.1

Question 14

Bottom Patch - Maximum thickness of lap-patch in critical zone

Answer 14

1/4”

653: 9.11.1.2.a

Question 15

Weld Qualification – When can UT be used in lieu of RT to Qualify a Welder/Welding Operator

Answer 15

> 1/4”

IX: QW-191.2.1.a

Question 16

Brittle - Thickness when brittle fracture is NOT a concern

Answer 16

< 1/2”

653: Fig. 5.1

Question 17

Shell Patch – Max shell thickness when lap-patches are allowed

Answer 17

1/2”

653: 9.3.1.2

Question 18

Shell Patch – Maximum patch thickness for a shell lap-patch

Answer 18

1/2”

653: 9.3.1.3

Question 19

NDE - When welding existing shell plate. Thickness that requires 100% examination by RT and MT or PT.

Answer 19

> 1”

653: 12.1.5.1.

Question 20

NDE - Plate thickness which requires 100% of verticals weld to be radiographed

Answer 20

> 1”

650: 8.1.2.2.c

Question 21

Reconstruction - Shell plate thickness that requires all welds to be preheated to at least 200 F.

Answer 21

> 1-1/2”

653: 10.4.4.3

Question 22

Shell Pits - Minimum remaining thickness allowed below a pit

Answer 22

½ tmin

653: 4.3.2.2.a