Qualified Production Base Metal

Date 12-07-2001 19:04

Per ASME Section IX QW-351, "A welder shall be requalified whenever a change is made in one or more of the essential variables listed for each welding process." All of the processes listed use paragraph QW-403.18 to describe the change in P-Number as an essential variable. Since QW-403.18 says that requalification is required by "A change from one P-Number to any other P-Number or to a base metal not listed in QW/QB-422 except as permitted in QW-423, and in QW-420.2.", the limits of those two paragrpahs govern. Paragraph 420.2 talks about P-Number/S-Number cross qualification, which is a different issue. Therefore, QW-423 says that a welder who qualifies on P-No. 1 material, they are qualified for "P-No. 1 through P-No. 11, P-No. 34, P-No. 41 through P-No. 47, and unassigned metals of similar chemical composition to these metals." To boil it down, if a welder qualifies on a P-No. 1 materail, he or she is qualified to weld any ferrous and nickel based alloys, and some copper based alloys.

"Base Metal(s) for Welder Qualification" is what base metal the welder used when he/she did the welding test. "Qualified Production Base Metal" is what the welder is allowed to weld on if they are following the rules of Section IX.

G Roberts

By RonG

Date 12-07-2001 20:22

As soon as my head stops spining I will put my 2 cents worth in.

I think the answer to your first question is no! (QW-403.18) a change is a change.

I belive QW 423.1 is explaining that when referencing a WPQ to a WPS,
if the WPQ base material is not listed in QW/BW-422 but has the same mechanical and chemical properties as the P-No listed in the WPS, then that P-No. my be substituted on the WQR.

If you read the table in lower part of QW-423.1 from left to right it gets a little clearer.

The left side being an example condition and the right side the rules governing it.

And then read on to QW-423.2

By MBSims

Date 12-08-2001 06:32

I have to disagree - a welder CAN qualify on P-1 and the range of P-numbers he is qualified to weld is P-1 thru 11, P-34, and P4X. The catch is that F-No. is also and essential variable, and a qualification with something like F-4 or F-6 does not qualify for the nickel base electrodes that would typically be used on P-34 or P-4X.

Marty

By - Date 12-08-2001 20:06

I absolutely agree with Mr Sims and Roberts.

To address an issue raised by RonG: Just keep in mind that procedure qualification and performance qualification are two completely different things. Many people think that the welder needs to be qualified to a procedure. This is incorrect. He is qualified to the WELDER variables. These are totally independent of the procedure variables. The welder must however follow a qualified procedure while being qualified.

Regards
Niekie Jooste

By RonG

Date 12-10-2001 13:24

I have to admit I am of the same inpression on the P-No.s and have set up our training matrix with that in mind using the Process, F-No.s and backing as separators, but it does say "A change" How Ever.

QW-200.3 alludes the the P-No. system was established to reduces the number of PQRs and WPSs, where as QW-300.1 and on (Welder Performance Qualifcation) only says a change in essential variables ( P-No. being an essential variable).

Is there any Philadelphia lawers or Supreme court justices out there that want to comment? I would Like to know the answer my self.

By - Date 12-10-2001 17:14

I do not think that you need any lawyers here. All the welding engineers (Including myself) and inspectors interpret it this way. Everyone that taught us how to use the codes also interpret it this way. Just read the code!

The way to use ASME IX when interpreting variables, is to start at the relevant table listing the variables. Then follow the referenced paragraph numbers. Those paragraphs will again reference you and so on, till you get to the answer. You must never jump to the reference section (Data section) without being referenced there from the other sections.

Regards
Niekie

By pipewelder_1999 (****)

Date 12-10-2001 18:06

In regards to "If a welder qualifies using P1 material are they qualified to weld on P numbers 1-11 as stated in QW 423.1? " the answer in my opinion is "Yes" provided the remaining variables for which the welder qualified remain the same.

A welder qualified with carbon steel base metal and filler metal is in some cases qualified to weld stainless. But you must look at ALL of the variable ranges for the weld. If the test was given for GTAW with ER70 type wire (F-6) then the welder would be qualified to GTAW weld SS Pipe (P-8) with Er-30x wire. However if the test given was SMAW with E-7018 the welder would not be qualified to weld with SS Stick due to the change in F-No. F-4 vs F-5 (Aust)

There may be paragraphs in section 4 that apply both to welder and procedure qualificaction but you must use the paragraphs as indicated by the applicable table for performance or procedure qualification. I have seen in many occasions a company give both a GTAW CS test and a GTAW SS test.

This is beyond what is required by code but so many of us are so much smarter than those guys that sit in the code commitee meetings. However we all pay for this added (Knowledge).
Have a good day

Gerald Austin
http://www.weldinginspectionsvcs.com/