Welder Re-qualification / Previous Welds 1

[GregLamberson]

We are fabricating offshore jackets to AWS D1.1 and are having quality issues with welding (this is in a W. Africa fab shop). Due to a high repair rate, we are going to ask for some welders to be re-qualified. Question, if a welder fails his re-qualification, does that call in to question the welds he has welded on previously.

The question seems a bit ridiculous on one hand because if the weld passes NDT, then what's the problem? On the other hand, taken to its logical conclusion, then why have any qualification standards at all, WPS's, PQR;s etc, just let the guy weld and if it passes NDT great.

I have looked thru AWS D1.1 Sections 3 and 4 and don't find any direction.

I would like to get some thoughts on the matter.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy

Website:

http://www.oil-gas-consulting.com

 

[unclesyd]

Can you post your NDT procedures used on the project for inspection?

 

[GregLamberson]

unclesyd

Unfortunatley I do not have them electronically. We are doing UT, MPT, and radiography.

This is a situation of coming in to the project at the tail end and finding some quality deficiencies and trying to make the best out of a bad situation. One thing we have started doing is classifying welds for criticality.

And while we've asked for some welder re-qualifications, it's kind of like the dog chasing the car, you catch it and what do you do with it. I understand from D1.1 (4.32.1.4) that once a welder fails a re-qualification, he must undergo re-training prior to attempting again.

But again, what I am not sure of is how to handle the welds he did work on. Can we accept them without exposing the company to risk?

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[metengr]

Question, if a welder fails his re-qualification, does that call in to question the welds he has welded on previously.

Yes, I believe it does. You have uncovered a quality problem or nonconformance that requires a disposition. Regardless, of when it was found it needs to be dispositioned.

If I was the customer, I would require the fabricator to go back and re-examine a percentage of the welds (say 10% to begin) that were deposited by this welder (if traceable). If you cannot trace the welds, I would go back and examine a 10% sample for starters. If during this production inspection any of the welds did not pass NDT, all of the welds would be suspect, and need to be examined and repaired by a qualified welder.

 

[GregLamberson]

metengr

You don't know how much I appreciate your input. I know this is a forum and the idea is to exchange information, but I owe you.

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[SJones]

Take a look at UK standard EEMUA 158 to get guidance on categorising welds with respect to NDT criticality and how to deal with reduced quality welding. It's got a bit more 'meat' behind it than D1.1. Firstly though, make sure that the repairs are due to welder skill problems and not procedural problems. Even the best welders will struggle if the procedure isn't right. On the critical welds, it should have been 100% NDT anyway so you should have caught all the problems within the detection capability of the NDT procedures employed.

Finally, check the contract. Most oil company's contracts give them the right to reject any welder for whatever reason.

The aim of qualification is to demonstrate that a welder is capable of making satisfactory welds. The aim of quality control is to ensure that the welder's resolve to make satisfactory welds doesn't lapse!

Good luck with sorting out the radiographs and the UT reports!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[metengr]

SJones makes a good point regarding weld procedure, qualification and NDT. However, one point that I would not agree on is to justify re-evaluating the criticality of welds for new construction, after the fact. This should be done up front before a contract is awarded. If the customer's contract requires specific NDT requirements or a quality level you are bound by this unless the customer is willing to negotiate or settle for an alternative approach.

 

[SJones]

The "reclassification" is probably aimed at identifying welds for a re-NDT exercise which will most likely be at the purchaser's expense!

Greg - whilst you are worrying about the welders did anyone think of cross-checking the NDT?!!!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[GregLamberson]

Steve

We are in the process of doing that now, allot of things going on in parallel.

We arrived to site as a new team on Week 33 of the project (this is a sub-project within the project, I also have 3 other sub-projects, all challenging but not quite so much so as this one), so to say we have stepped into a situation is putting it mildly.

We do not yet have all of the PQR's done (load out is scheduled for early January!), some repair procedures have not been run yet, traceability of the welders is spotty. We have welds that are filled and capped and the welder matrix is only filled out for the bead & HP. UT contractor is suspect, we are running some traps on him at the moment.

But you know what - that's part of it, got to look for solutions rather than dwelling on the problems.

Metengr

Agree 100% on the criticality assessments, however, as per the above, that was not done. So the only option I have is to evaluate the criticality now so as to be able to focus minimal resources and little time to get the biggest bang for the buck. At the end of the day the client will have to decide if we sailaway or not.

I really do appreciate the input

Greg Lamberson, BS, MBA
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[SJones]

Please let me know what platforms these are so that I don't end up visiting them!

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[gtaw]

I have been involved on projects where welders that failed to meet the project requirements were required to retest. Those welders that failed were "fired" and all their weld cut out and rewelded by qualified welders. On other projects, questionable welds were subject to 100% NDT (usually UT for CJP and MT for fillets and PJP welds). Unacceptable welds were repaired so they did meet the acceptance criteria.

As mentioned by "Metengr", it is best if these contingencies are addressed in the project specifications before the project starts.

Best regards - Al

 

[Ron]

GregL...yes it calls past welding into question. The way we usually handle that is to go to 100 percent NDT on that person's welds, at least until there is a comfort level that the in-place welding is OK.

 

[GregLamberson]

Much thanks to all for providing your experience and input. I'd like to extend a merry Chrstmas and happy new year.

Greg Lamberson
Consultant - Upstream Energy
Website:

http://www.oil-gas-consulting.com

 

[SindelA]

Gentlemen,

As for the AWS D1.1 Code, there are no requirements to go back and re-inspect the other welds that were done prior to the request for "Requalification". I must add now in my opionion and not of the AWS or AWS D1 committee.

The AWS D1.1 Code does not require NDT unless a specific splice in a beam.

Therefore any other NDT, other than visual, must be specified in the contract. As such, terms like Spot, which can become progressive evaluations due to the lot evaluation being un-acceptable, would force additional NDT of the prior welds.




Regards,

Allen
Sindel & Associates

http://www.consulting.awsindel.org