Welding A333 Gr.6 ASME 31.3

You must read B31.3 starting at 323.2.2 and Table A-1. Follow the requirements, it is self explanatory.

metengr, could you make clear that the 323.2.2 covered for welding in manufacture and fabricator by the detail?

On table A-1 for A-333 Gr.6 the lowest temperature for which impact test is not required for the base metal is -43°C.

Therefore for the cases above Column A of table 323.2.2 is applicable (Design Minimum Temperature at or Above Min. Temp. in Table A-1).

A-333 is not assigned on table A-1 to any curve of FIG. 323.2.2A. Therefore acc. to table 323.2.2 A-3(b) for:
#1: the design temperature - 39: HAZ and weld have to impact tested (MDMT < -29°C)
#2: the design temperature - 20: HAZ and weld must not be impact tested (MDMT ≥ -29°C)
#3: the design temperature - 43: HAZ and weld have to impact tested (MDMT < -29°C)

Regards - Juergen