ASME IX 3

[chtimi]

I would like to understand ASME IX concerning welders qualification.
QW 350 gives essential variables. For SAW, P Number is an essantial variable and we have to see QW 403.18.
QW 403.18 gives “ a change from one P Number to any other P Number or……. exept as permitted in QW423, and QW 420.2.”
We have a welder qualified with a base metal P N°1.
Is it Qualified for P N°1 through PN°11?
Alternatively, is a welder qualified for a PN°11, qualified for PN°1?
I would like to understand the exeption.
Thank you for your answers

JL

 

[metengr]

Yes. The exception to a change in base metal P-No that you refer to in QW 403.18 is for welder qualification purposes. The base metals that are assigned P-No's or S-No's in accordance with QW 420 are used to permit a welder to qualify on a range of P-No (420.1) or S-No (420.2) base materials using only one of the base metals within the specified range, as indicated in QW-423. So, if a welder chooses any one of the base metals within the P-No1 thru P-No11 or S-No1 thru S-No11 range to qualify on, they are qualified for the specified range of base metals.

 

[VeryPicky]

Don't forget P34, or P41 through P47. These belong to the same "group" as per QW423.1. Otherwise all perfectly correct. And, yes, that does apply to welder performance qualification only not to procedure qualification record.

 

[croy2]

As someone mentioned in a different, similar post it probably wouldn't be a good practice to allow a welder to qualify on mild carbon steel (P-1) and then go weld 9% Cr material (P-5b), which is obviously a much more difficult material to work on.

 

[lostsailor]

and also bear in mind that base metal substitution can only be done assuming all other essential variables remain unchanged

 

[cedeng]

...as the filler metal. Welder will not be able to weld P8 for example (which is SS) if he is qualified P1 with filler metal F4, filler metal for P8 is F5 !!! So he can weld P8 but with the same filler metal than qualification on P1...isn't amazing...

So , if I'm all right, this is an example of where ASME is a little stup.d and why it is so difficult to understand...

is Anybody approve what I advance ?

 

[metengr]

I am not sure I understand your point. Welder qualification was established by Section IX of the ASME B&PV code to demonstrate that a welder can deposit weld metal of sound quality. This process was not meant to demonstrate weldability of materials- like a weld procedure qualification.

 

[weldtek]

For anyone wanting a better understanding of ASME Sec IX, I'd recommend the CASTI Guidebook for Sec IX. It provides some valuable insight from authors who have served on the Code committee.

 

[VeryPicky]

I support meteng.
Welder test in meant only to proove welders' ability to weld with specific filler. It has very little to do with the base metal.
For establishing weldability PQR is required.


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