Thicknesses Flashcards
Bottom - Minimum allowed bottom plate thickness when there is a Reinforced Liner that is > 0.050” thick
0.050”
Bottom - Minimum allowed bottom plate thickness when there is a means to Detect and Contain a leak
0.050”
Roofs - Minimum allowed average thickness of corroded roof plate
0.090” in 100 in2
Shell - Minimum arbitrary shell thickness (used when calculated minimum thickness is below this number)
0.100”
Bottom - Minimum allowed thickness of bottom plate at toe of the external shell-to-bottom fillet weld
0.100”
Bottom - Minimum allowed bottom plate thickness away from critical zone or an annular plate
0.100”
Bottom - Minimum allowed plate thickness in critical zone that can be repaired by weld-buildup
0.100”
Roof Rim - Minimum allowed roof rim thickness
0.100”
Roof - Minimum thickness of new roof plate (cone & floating)
3/16”
Roof Rim - Minimum thickness of new roof rim
3/16”
Bottom - Normal minimum thickness of new bottom plate
1/4” (0.236”)
Bottom Patch - Maximum thickness of lap-patch in critical zone
1/4”
Brittle - Thickness when brittle fracture is NOT a concern
1/2”
Shell Patch – Max shell thickness when lap-patches are allowed
1/2”
Shell Patch – Maximum patch thickness for a shell lap-patch
1/2”
Weld Qualification – When can UT be used in lieu of RT to Qualify a Welder/Welding Operator
> 1/2”
-
NDE - When welding existing shell plate. Thickness that requires 100% examination by RT and MT or PT.
> 1”
NDE - Plate thickness which requires 100% of verticals weld to be radiographed
> 1”
Reconstruction - Shell plate thickness that requires all welds to be preheated to at least 200 oF.
> 1-1/2”
Shell Pits - Minimum remaining thickness allowed below a pit
1⁄2 tmin
Linings - Thickness of a thin film lining
