Weld Repair

Date 08-20-2008 15:47

Hi Bert,
I don't think you will find it written anywhere in the Structural Welding code(AWS D1.1) specifying how many times a joint can be cut out and rewelded. However the project Engineer Of Record or the Customer may have written such a restriction into their project specifications. The main thing is that when it leaves the fab shop, that the joint in question is now acceptable per AWS D1.1(after visual, and appropriate NDE methods).

edit: BTW, it would be wise to put your best welders on this, so you don't have the 2nd and 3rd attempts at the repairs.

By js55

Date 08-20-2008 16:00

The other thing is, not wishing to cause a stir here, the third party inspector has no authority to unilaterally limit the number of repairs unless it is explicit in the contract docs. But, I would immediately open a dialogue with the EOR (which is what this third party &*%$head should have done)and come to a reasonable conclusion.
Too many inspectors are to ready to stroke their egos and toss their weight around. I mean, come on, you see a guy cutting a weld for the second time how much energy does it take to call your client?
But john is also dead on, it shouldn't take 3 or more times to make this weld. Use a better welder.

By CHGuilford (****)

Date 08-20-2008 17:10

The limits I have seen on repair work are found in D1.1 - 5.26.3. That does not exactly address your situation of slag, lack of fusion, and porosity. Although it does require the Engineer be notified if you have to cut the joint apart. The number of times to repair is not mentioned.

From your post, I can't tell if you are having to fix the same defects several times or if you mean there are several locations on the same lengths of weld joint. If you are having to fix the same defects several times, you might want to consider what is going wrong (welder skills. joint configuration, etc.) before you go much farther.
I don't think repairing a repair is ever a good thing to happen, but I have seen cases where difficult situations led to that. I feel that if the welding will be tough to do, then you should practice on a mock-up joint to minimize mistakes. I would also inspect every weld pass until you know the work is under control.

As far as the 3rd party inspector- I would check the contract carefully to see what authority he/she has. It might turn out that the inspector is imposing his personal views but has not the authority to do that. However consider his position on this - if you are in fact making repairs on repairs, that certainly doesn't look good for you.
However, I think the inspector should be contacting his client on how to handle the situation.

By jwright650 (*****)

Date 08-20-2008 17:29

Another thing to note adding a bit to Chet's reply see AWS D1.1:2006 paragraph C-5.26.1 that mentions the inspector's authority

.... regarding these rejectable indications found by UT: see paragraphs in AWS D1.1:2006 6.26.9, 6.26.10, and 6.26.11 regarding the UT reports.

By bert lee (**)

Date 08-21-2008 01:00

thank you guys, i did ask the 3rd party on his basis and why we cannot not make weld repair after the 2nd attempt......and he told me that there will have an affect on mechanical properties (we are only using A36 material) if more repair welding been done on the same spot of the weld. I asked politely for any supporting document that we can refer but he told me to attend a welding course instead., he even told me that he also have the power to remove me from this project if he wants.

If its critical...then why it was not stated on D1.1 the number repair work allowed.

regards
bert

By 803056

Date 08-21-2008 04:09

Ouch!

You have a problem child on your hands. I believe you have a better reason to have him removed from the project than vice versa.

As stated in a couple of earlier responses, AWS D1.1 does not address the number of repairs. Unless there is a clause in the project specification addressing or restricting the number of repairs on a welded joint, this individual is stepping way over the border.

It is not the third party inspector's prerogative to rewrite or modify the contract or project specification.

Again, with out knowing all the details, Monday morning quarter backing is always dicey. However in this case I would pass you concerns "up the ladder" to someone in your organization with higher authority. Voice your concern that the third party inspector is interfering with production and causing needless delay. If the TPI is having any heartburn about what you are doing or how you are doing it, he should be communicating his concerns to the EOR, the owner, or his client. They should be the parties communicating with your employer that there is a serious concern and they should be negotiating the "new requirements" if such restrictions, limitations, or conditions are not addressed in the project specification.

It sounds as if the TPI may have an ego a tad greater than his authority. In my twenty years plus as a TPI, I've never had the authority to "stop work". I have always had to pass my concerns on to the owner or his Engineer of Record. It was always the owner or his design professional that had the authority to issue a "stop work" order. You may be in a different situation, but the contract should clearly delineate who wields the power to stop work on the project.

I don't totally disagree with the TPI. If you have attempted to repair the same defect several times, it is time to step back and detemine what the root cause of the problem is rather than simply having the welder gouge the weld out again and again. How was the defect detected? Is the location of the defect in the same place each time. If UT was used, was it properly calibrated for distance and was the location of the defect, i.e., depth, properly determined? I'm sure you have considered those issues already, but there is no harm in double checking. Once again, you didn't provide much detail, but there are many things to consider when making a repair especially if the first attempt to make a "simple" repair proves to be unsuccessful.

I've been hired to write specific repair procedures to ensure the welder knew what he was expected to do and how to the repair was to be accomplished on critical repairs. In a some cases the proposed repair procedure was required by contract to be reviewed and approved by the "owner". The simple act of writing the repair procedure forces you, or at least it gives you an opportunity, to give due consideration to nature of the defect and how to remove it, prepare the area for welding, and the sequence of making the repair. Nothing forces you to think about a problem like writing it down on paper.

There are times when the contractor has asked for my opinion (as a TPI), but I always make it clear that I am only making a suggestion at their request and I am not "requiring" the contractor to do anything. The method and means is always the fabricator's responsibility, not mine. Likewise, the responsibility for success or failure is the fabricators.

There also those projects where the fabricator doesn't ask for an opinion and that is perfectly fine with me. In those cases I simply step back and let them sink or swim on their own accord. As a TPI, I am not the fabricator's welding consultant and it is important that I don't become part of the problem. There are plenty of consultants that are willing to help solve the problem if there is enough money involved.

Like your TPI, I have suggested specific training courses offered by AWS, ASM, or ASME. A recent project required me to review the WPSs for a piping system. The QC person clearly didn't know how to write a WPS or how to properly qualify a welding procedure. He asked where he could learn to develop welding documentation, so I recommended he attend an AWS CWI seminar and Walter Sperko's ASME Section IX course. He took my advice, he attended both courses, and he thanked me for suggestion.

For a closing comment, I suggest that you try to consider the TPI concerns. Your TPI may not have the best interpersonal skills and he may be over stepping his authority. It also sounds like he is stepping on some toes in his attempt to maintain a high level of quality on "his" project, but I'm sure he has the project's best interest in mind.

Good luck.

Best regards - Al

By 3.1 Inspector Date 08-21-2008 06:57

I think Al hit it on the spot!
Most(if not all) client specs that I have come across actually limit the number of repairs to 2.

I assume that you have allready checked your specs....

By Mikeqc1 (****)

Date 08-21-2008 15:58

I can recall a few state DOT special provisions limiting the number of repairs on projects, and vthey had the power to request a requal based on workmanship.
And as far as the inspector being a problem child there was one case of an inspector preventing a job from shipping on a friday because of a problem he found on monday but didnt tell the shop, this man was banned from the shop.
MDK

By jarcher (**)

Date 08-21-2008 08:49 Edited 08-21-2008 09:03

Hi Bert, everybody else has done a masterful job of defining the TPI's place and authority in your project, but I'd like to address it from another angle just because I've run into it a couple of times: that is how confident are you in your UT technician? Are your projects regularly plagued with repairs and rerepairs? IOW do your welders display significantly better performance most of the time, but somehow this particular project is just snake bit. Don't get me wrong, snake bit projects do happen, but so does NDE incompetence or worse. I can recall a couple of times where I have come in contact with this. Once a place where I worked had a time critical project, a pressure containing pipe spool with a 4" weldolet. The pipe was 24" I think, both circumference welds pipe to flange RT'd fine. The weldolet was also to be RT'd, uncommon, but that's what the people were paying for. So the boss came out and told me that there was a rejectable defect in the weldolet. He got a UT hand out to help me locate it so it could be repaired. The technician keep telling me it was 2 3/4" deep, so I would gouge out the weld to 3" or 3 1/2" deep and reweld. This went on for two days. Finally on the third day the boss came out in the shop early and asked the technician "Hey do you know so and so at such and such lab?" The technician replied "Sure, he's my boss." The owner (my boss) then said "Well, you know, I've been doing business with him for 25 years now. I think I will call him and ask him if he can't get me a UT technician out here." Very next scan the depth of the discontinuity was 4 1/2!" I said "Wait a minute, lemme see that radiograph." Should have done that in the first place - duh. Turned out to be a slag line laying right on top of the root pass. Took me about 15 minutes to back gouge the root and weld it up. Clean radiograph.

More recently, working for another company, we had a frame of TKY construction with about 150 CJP welds welded from one side. We used a contractor that came highly recommended by the TPI. Technician comes in and calibrates, has nothing to say to me, who was his liaison with the paying customer, puts on a big show for the major oil company observers and the TPI, and starts rejecting welds left and right. He rejected 49 out of 150 welds. Early into this circus, I headed into the office and caught the owner and the QA manager and told them this guy was raping us, he couldn't possibly be finding as many rejects as he was marking up. We spent a very long day grinding/gouging welds and finding nothing with either MT or PT. The NDE service's level III came in and told us at the end of the day that he was there to prove his man was right. No "Let's see what we can see.", "Let's see what is going on here." LOL, they didn't even have a TKY procedure. We brought in another NDE service the next day and their technician found 4 rejectable spots. The first service, as I understand it, has gotten out of field work entirely at the present. All they do presently is straight beam on forgings.

The point of all this is that if your welders are not finding any discontinuities when they excavate, something could well be wrong with the markup. If its tubular TKY make sure these people know what they are doing, you should have a copy of their TKY procedure and assurance from their level III that the technician is trained on it.

I notice that the first response here was that incompetent welding was an issue. Well that might be, if its one or two or three of your welders that are responsible for the bulk of repairs, then that's probably it. If its spread around equally, then it could well be the NDE, appropriateness of the WPS, consumables, any of a number of issues that need identification and correction.

Edit: I notice Al addressed the NDE issue so my input is not entirely in a different vein from the thread. But when I see people making multiple repairs on welds, it immediately raises that flag with me. Especially if its a case of the defect not being found by the welder when excavating the weld and having the same defect remarked.

By jwright650 (*****)

Date 08-21-2008 11:08

I've been bouncing sound for a few years myself, and I agree with your observation in this thread...the UT tech could be mis-interpreting what he is seeing, or mis-marking where the rejected indication is...I have seen both with 3rd party inspectors that visit my shop.

I had one guy from a very reputable inspection agency marking up every joint that he inspected the first day he was here. I didn't really question the first one, but when he marked the second one, I went and got my UT machine to see what in the world was going on. I didn't find anything in that joint, so I had him come back and show me what he was finding, so I would have an idea what we were up against...he had just been issued this new piece of equipment and had never even coupled it to a IIW block, he just took it out of his truck and brought it right in and started inspecting....so I lent him my cal block and watched him struggle trying to do a calibration. He flipped the block over several times and was mumbling the whole time....needless to say, I UT'd everything myself before letting this guy couple to any of my steel.

By bert lee (**)

Date 08-22-2008 15:21

the only thing i don't understand is whether the TPI has the right to impose restriction on the number of repair to be allowed on same weld joint when its not mentioned in the relavant code and project specification.

anyway, i got many good answers from you.

thank you

bert

By HgTX

Date 09-02-2008 23:00

If it's not in the contract documents, he can't require it. That said, there are a lot of people out there with the impression that 3rd-time repairs are not allowed. My DOT's specs used to disallow it, till they adopted D1.5, which doesn't say anything. In a legal fight, I suppose he might be able to argue from "industry common practice". (I'm not saying he'd win, just that he could argue it.)

Hg