Welder Qualification 1

[tekari123]

Dear All,

As per QW-423.1 does a Welder qualify to make the production welds with P-8 material who is actually qualified with P-1 material while performing the qualification test ? Kindly explain.

 

[metengr]

Regarding welder qualification, the issue is about depositing specific filler on a wide range of base materials to avoid more performance tests then necessary to qualify a welder. The purpose for welder qualification is to demonstrate the welder can follow directions using a WPS and can deposit sound weld metal. The committee tries to minimize the amount of performance testing required by maximizing the number of base materials that can be grouped together to qualify a welder.

 

[tekari123]

Thank u for replying.
do you mean to say that a welder can weld P8 Material having welder qualification with P1 material, with same filler used in qualification??

 

[metengr]

The welder has to qualify for both base metal and filler metal. You have the permitted range of base materials established, now the filler metal must be qualified.

 

[gtaw]

P-number: categories of base metal
F-number: categories of filler metals
A-number: categories of weld chemistries

Welding process, position, weld type, P-number, F-number, etc. are essential variables when qualifying the welder. One must study Section IX to determine what ranges (for each essential variable) the welder is qualified to use in production.

If the welder is qualified using a P1 base metal, he is qualified to weld a wide range of base metals including P-1, P-8, P-40, etc.
If the welder is qualified using an F6 filler metal he is qualified to weld with any F6 filler metal provided it does not involve a change in welding process. All of this assumes the contractor has qualified WPSs to cover the ranges for which the welder is qualified.

Best regards - Al

 

[DekDee]

Al / metengr,
Just a hypothetical for your thoughts.

Welder who qualifies on P1 material (F6) is then qualified to weld P8 material(F6).
Addition of purge (inert backing gas) for welding the P8 - no problem.

Welder who qualifies on P8 material (F6) is then qualified to weld P1 material(F6).
Deletion of purge (inert backing gas) for welding the P1 is an essential variable.

So, a welder qualified on P8 can only weld P1 if it has inert backing gas.

Your thoughts ?,
Cheers,
DD

 

[tekari123]

Suppose a Welder qualifies in P1 with F4 then per the above explanations he qualifies also to weld P8 with all F4 but what about the WPS which allows F6 fillers only..?? How to overcome such situations..??

 

[DekDee]

tekari,
The welder qualification range is much wider than the welding procedure range - as mentioned above one is related to the welders ability and the other to the chemical / metallurgical properties of the resultant weld.
A welder can only use the qualifications he has if the company has WPS's to support those qualifications.

Your question is very strange because you are asking why a welder qualified on F4 (SMAW)cannot weld a WPS qualified with F6 (GTAW) - probably because they are different processes.
Regards,
DD

 

[gtaw]

In addition to the welder's qualifications, one must consider the WPSs which are qualified by the contractor and available for use by the welder. If the contractor does not have a qualified WPS, the welder's qualifications mean very little. The welder may be qualified for a range of materials, a range of base metal thicknesses, etc., but the qualifications are meaningless without a qualified WPS to support the production welds.

The essential variables that apply to the welder are not the same a those that apply to the WPS and supporting PQR. Regardless of the welder's qualifications, he must follow a qualified WPS in order for a weld to meet ASME requirements.

Best regards - Al

 

[metengr]

DekDee;

So, a welder qualified on P8 can only weld P1 if it has inert backing gas.

Using F6 filler metal with the GTAW process, yes, correct. For many high pressure boiler tubes and piping of carbon steel, use of the GTAW process requires backing gas to pull a quality root.

 

[XL83NL]

Don't have much to add or comment to posted useful replies.
For the discussion, some of you might enjoy the ASME (freely distributed) White Paper on "Auditing of Welding Under ASME Section IX", which provides useful insight on some of the subjects discussed here (or just go to the Sect IX subsection page and look at the left).

The ASME BPV Subcommittee on Welding and Brazing (Section IX) has recently prepared a White Paper aimed at providing guidance when conducting surveys in evaluating welding as a controlled manufacturing process. The document is extremely useful not only for auditing purposes, but also for training and as a support when reviewing documents related to welding procedure and performance qualification.

The White Paper is divided into two parts:

Part 1 details what needs to be covered on a Welding Procedure Specification (WPS) and a Procedure Qualification Record (PQR) relative to the requirements of Section IX. It provides specific examples and suggestions.
Part 2 has been written for auditors to help them to understand what Subcommittee IX thinks manufacturers and contractors should have under control when using welding as a manufacturing process. It sets out a method for demonstrating that WPSs have been properly implemented, as well as providing specific suggestions regarding technical aspects of welding that could be examined to establish the level of competence of the manufacturer or contractor.

Regards

 

[DekDee]

metengr,
Thank you for your response.
The issue came from an arguement I had with a colleague regarding the use of "As required" or "with / without" on a Welder Qualification certificate in the space for Inert Gas in the "Qualified for" column.
If it was a P8 qualification then "As required" (IMHO) is not acceptable as again in my opinion that is based on does the WPS require it ?
Maybe I am making a big deal over nothing but I have reviewed hundreds of welder quals over the years with the two statements above noted and I have never ever seen anything noting purge required for P1.
As it never affected the particular project I was on I never made any comments about it.
Cheers,
DD

 

[stanweld]

If the welder qualified without backing gas, he/she is qualified with & without backing gas. If the welder was qualified with backing gas, he/she is only qualified to weld with a backing gas unless he/she is welding into a backing strip or making a double sided weld.