Grinding during PQR & Welder Qualification

By Lawrence (*****)

Date 02-17-2011 15:40

Nalla

Do you not have a copy of the codes yourself?

You are a QC inspector.

This is not a question that would be asked by an inspector with the code book in his hand.

If you don't have the codes in your hand you are not/cannot be doing your job correctly.

If you have a specific question about a part of the code or how it should be understood that's one thing. Your question is quite another in my opinion.

By Nalla

Date 02-17-2011 22:00

Lawrence
I have AWS D1.1-2006 & ASME SECT IX-2007- I cannot find anywhere grinding totally not allowed
It is normal practice just chip and little grinding at start and stop area before depositing next run.
Attendng client inspector insists totally no grinding allowed.
Pls advise

By Lawrence (*****)

Date 02-17-2011 23:29

If attending client inspector is unwilling or unable to indicate by section and paragraph, exactly which part of the code he is using to make his restrictions he is not doing his job correctly.

By Tommyjoking (****)

Date 02-17-2011 23:49

I agree with Lawrence. Inspectors job is to interpret the code and apply it...not add or subtract from it as they see fit. Make him quote the relevant section to you.

By welderbrent (*****)

Date 02-17-2011 23:46

What does your WPS call for in order to clean between passes?

Otherwise, I agree with Lawrence, make him give the reference for not allowing it.

Have a Great Day, Brent

By jarcher (**)

Date 02-18-2011 01:36

In my experience a lot of welder qualification testing is more stringent than the code (whichever one it may be) requires. I've seen instructions that allow no grinding other than for feathering tacks in the root. I've seen demands that the root on a 6" coupon be run with no more than three rods. Some places I know of require weld completion within a certain amount of time. None of the codes I work with regularly address the issue of how much or how little grinding is allowed for WPQ tests. The bottom line is though, the employer can require virtually anything of the welder in order to hire him, at least in the states I've worked in. The test must be welded with limited accessibility? Only a wire brush can be used to clean the weld? The coupon must be welded using a mirror? The employer can require any of these conditions in addition to the ones the code books do specify in order to produce qualification of the welder.

By Tommyjoking (****)

Date 02-18-2011 01:43

Well Brent did mention the WPS......and that is true you can put in anything you want in the WPS.....

By jarcher (**)

Date 02-18-2011 04:33

Doesn't have to be in the WPS. If the contractor or fab shop owner says to the job applicant: "I'll hire you if and only if you weld up this pipe in 6G while standing on your head.;" the welder should weld the test standing on his head if he really wants to be hired. Of course he would have to follow the WPS in making the weld, but he would also have to stand on his head. He could of course whine about how it was all so very unfair and the guy that thought the requirement up was a SOB and he was gonna sue, but I doubt that would get him the job, and in most states in these United States he would lose his lawsuit to boot.

By Lawrence (*****)

Date 02-18-2011 02:23

Of course a player can add criteria exceeding the code.

But the original poster has made it clear that he already has a contract, *client inspector* right?

So while the code can be exceeded... It's not some arbitrary lipservice from the client inspector. If the agreed upon criteria is the code and nothing more, than the code and nothing more is all that is required.

By jarcher (**)

Date 02-18-2011 04:19

Lawrence I really don't see the client inspector angle in the original post, even upon rereading it. Its certainly not explicitly stated, and I don't read minds.

By Shane Feder (****)

Date 02-18-2011 04:51

jarcher,
Have a look at Nallas second post !
Regards,
Shane

By Shane Feder (****)

Date 02-18-2011 05:08

Not sure if this helps,
ASME IX Interpretation IX-83-149
Question 1: In reference to the 1983 Edition of Section IX, QW 301.2, may the supervisor conducting the tests set his own visual requirements prior to the mechanical testing listed in QW 302.
Reply : Yes
Not sure if this is applicable to Nallas situation as this interpretation seems to lean more towards no grinding on finished weld prior to testing.
Regards,
Shane

By jarcher (**)

Date 02-18-2011 13:58

My bad, Lawrence said original poster, NOT original post. In which case Lawrence is exactly right, a client inspector can't add or subtract to the code requirements unless there is some provision for specifics in WPQ testing in the contract, which is highly unlikely.

By Joey

Date 02-21-2011 06:44

Nalla

I agree with Brent, if a WPS stated the method of cleaning is by brushing and grinding for the initial and interpass cleaning then the client inspector should not disallowed it.

It is not specifically mentioned in AWS D1.1 or ASME IX that grinding is prohibited during qualification test, in fact the practical solution on removing certain type of discontinuities is by “grinding” (you can refer to API 577).

In my opinion, the reason on why the client inspector do not want to use grinding is because of the longer time being spent on grinding than welding.

However, if that will be the case, the following statement may be applicable

In ASME IX – it says “The performance test may be terminated at any stage of the testing procedure, whenever it becomes apparent to the supervisor conducting the tests that the welder or welding operator does not have the required skill to produce satisfactory results”.

Boleh? :)
Joey

By Nalla

Date 02-21-2011 12:32

Dear Experts
In WPS stated- cleaning by brushing or grinding.
But how much and/or to what extent grinding can be allowed?
Is grinding the whole circuferentila weld can be allowed?
Yes, i did not come across codes prohibit/define extent of grinding.
That's why it can be always can be subjective to the attending supervisor witnessing the test.

By dbigkahunna (****)

Date 02-21-2011 13:13

If this is pipe and Section IX the industry practice is for grinding and mechanical brushing the entire weld. This makes for a better weld period.
I broke out years ago where grinding was not allowed on the bead pass. The industry has found proper grinding eliminates a lot of issues and the ground bead makes for a much better weld.
However, if the testing inspector is following the client/customer's wishes or the parameters are clearly stated before the testing and everyone is tested and evaluated the same way, there is nothing that would prohibit what the inspector is doing.
I will let you know a satisfactory weld can be made without grinding and hand brushing the weld. But it takes a much better welder to do it. And what it takes to do it is not taught to welders today because there is no reason to make the welding harder.

By Joey

Date 02-21-2011 14:57 Edited 02-21-2011 15:00

Nalla

Alamak Kawan, tabo leh tahan! :)

I think yourself will have a hard time to convince your client...the best solution is to engage a no nonsense third party inspector to conduct the test and to deal with your client inspector.

Lloyds is quite popular in your place, are you stationed in JB? you can easily get one from Singapore.

Get those nasty one...I tell you, your client inspector will not dare to disturb you if you'll follow my advise.

By 803056

Date 02-21-2011 21:27 Edited 02-21-2011 21:29

The only welding code I know of that prohibits grinding or the use of hand tools to improve the weld profile is AWS D1.5 Bridge Welding Code.

I feel it is good practice to develop the performance testing protocol in writing so there are no surprises once the welder begins the test. I review the test rules with the welder so he is aware of the restrictions or limitations before testing has begun. It is fair to the welder and to the contractor and it minimizes the opportunity for the test witness (me) to interject his personal views once the test is underway.

As for the third party inspector or the client's representative getting in on the act, it isn't his prerogative to interject their personal opinions on the subject unless it is relative to a requirement listed in the applicable welding standard or project specifications. Acting as the TPI, I once witnessed a fellow evaluating bend test samples that had some small cracks on the convex surface. After some effort spent with a grinder the cracks disappeared and the "inspector" pronounced the welder "certified to AWS D1.1." As polite as I could be after witnessing the "test," I informed the "inspector" the bend tests failed when the cracks were noted. "But they weren't that deep!" was his response.

When I give a welder qualification test, I limit the grinding permitted on a structural plate test to cleaning the groove and adjacent base metal before fit-up. I do not allow any grinding on the test piece once the test has started. On a pipe test however, grinding is permitted. Grinding of the tack welds is encouraged, if there is incomplete joint penetration in the root bead, I allow a portion (30%) of the root to be removed and rewelded to correct the joint penetration. That isn't a blank check to grind every weld bead. At some point the inspector has to make a judgment call that the welder is not skilled enough to pass the test. The last thing the contractor needs on the production floor or job-site is a welder that spends 75% of his time grinding out bad welds. After all, the performance test is intended to determine if the welder has the skills needed to deposit a sound weld, not to determine if he knows how to handle a grinder.

If the welder performance testing is per AWS D1.1 or ASME Section IX, the extent of grinding allowed or the use of a power brush to remove slag is left to the discretion of the contractor. Both D1.1 and ASME Section IX are silent on the subject. It is usually in the contractor's best interest to ensure the welder has reasonable skills and doesn't have to grind every weld bead before depositing the next weld bead. Grinding is expensive and often times counterproductive. I cannot recount how many times I've seen welders ruin a perfectly good weld by "touching it up" with a grinder.

Best regards - Al