ASME Section VIII, Division 1, or ASME B31.3, and the project specifications?

Which one applies depends on what the item is. ASME Section VIII, Division 1 covers pressure vessels. ASME B31.3 covers process piping. For welded connections the vessel scope ends at the welding end connection for the first circumferential joint (U-1(e)(1)(-a)), and B31.3 takes over from there.

- Section VIII Div 1: how much radiography you need (full, spot or none, UW-11) depends on the joint efficiency used in the design. RT acceptance is in UW-51 (full) and UW-52 (spot). UT, MT and PT acceptance are in Mandatory Appendices 12, 6 and 8.
- B31.3: the extent of examination depends on fluid service. For Normal Fluid Service it's not less than 5% random RT or UT of circumferential butt and miter groove welds (341.4.1(b)). Category M needs more (M341.4), High Pressure has its own rules (K341), and severe cyclic needs 100% (341.4.3). Acceptance is in Table 341.3.2-1. In editions before 2024 that table is 341.3.2.

The project specification can add to the code but can never go below it. If the spec and the code disagree, check the order of precedence in the contract and raise a technical query. Always work to the code edition named in the contract, because clause and table numbers change between editions.

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