API 653 Data Sheets-Thicknesses

Linings- Thickness of a thin film lining 

Bottom- Minimum allowed bottom plate thickness when there is a reinforced liner that is > 0.050" thick

Bottom- Minimum allowed bottom plate thickness when there is a means to detect and contain leak

Roofs- Minimum allowed average thickness of corroded roof plate

Shell- Minimum arbitrary shell thickness (used when calculated minimum thickness is below this number)     653:  4.3.3.1

Bottom- Minimum allowed thickness of bottom plate at toe of the external shell-to-bottom fillet weld       653:  4.4.5.7

Bottom- Minimum allowed bottom plate thickness away from critical zone or an annular plate        653:  Table 4.4

Bottom- Minimum allowed plate thickness in critical zone that can be repaired by weld-buildup   653:  9.10.1.6.b

Roof rim- Minimum allowed roof rim thickness

Roof- Minimum thickness of new roof plate (cone & floating)   

Roof rim- Minimum thickness of new roof rim

Bottom- Normal minimum thickness of new bottom plate   650:  5.4.1

Bottom patch- Maximum thickness of lap-patch in critical zone  653:  9.10.1.2.a

Brittle- Thickness when brittle fracture is NOT a concern    653:  Fig 5.1

Shell patch- Max shell thickness when lap-patches are allowed   653:  9.3.1.2

Shell patch- Maximum patch thickness for a shell lap-patch   653:  9.3.1.3

Weld qualification- When can UT be used in lieu of RT to qualify a welder/welding operator

NDE- When welding existing shell plate. Thickness that requires 100% examination by RT and MT or PT    653:  12.1.5.1

NDE- Plate thickness which requires 100% of vertical welds to be radiographed

Reconstruction- Shell plate thickness that requires all welds to be pre-heated to at least 200° F   653:  10.4.4.3

Shell Pits- Minimum remaining thickness allowed below a pit  653: 4.3.2.2.a