ASME IX QW420.2 - P #s and S #s

[LanaCarrie]

I would appreciate if anyone could clarify something in QW420.2 for me. The statement I'm questioning (1st sentence, 2nd paragraph) is:
"...welding procedure qualification with a base metal in one P-Number (or P-Number plus Group Number) or one S-Number (or S-Number plus Group Number), qualifies for all other base metals in the same S-Number grouping".

I take this to mean that any P1 will qualify you to weld any S1, regardless of Group number (eg. P1 Gr.1 will qualify for a S1 Gr.3). Is this true or am I incorrect.

 

[metengr]

My interpretation is that you are correct, provided the welding procedure is not qualified with impact testing. For example, if you were going to qualify a welding procedure with impact testing requirements, the P-No and Gr-No are essential and supplementary essential variables, meaning any change in Gr-No for the same P-No material would require re-qualification.

Otherwise, a change in Gr-No for a specific P-No material is not considered an essential variable for the listed welding processes.