American Welding Society Forum
I have a doubt on welder performance qualification by AWS D1.1.
I need a welder for welding with and without backing. As far as I understood, for qualifying the performance of the welder, I have to use a coupon test that uses a backing strip. Thus, how can I have the welder qualified for root pass? The only way out I found in the standard that could give me a second option would be to qualify the welder together with the procedure qualification. But in this case, shouldn’t I use all mechanical testes, such as tensile, bend, etc? It is going to be expensive.
Thank you for your help.
under the standards at our school they use x-ray to check for proper penetration on the root .... hope this helps ....
Why would you need a qualification for a welder without backing? I think you may be confusing the requirements of another code (perhaps ASME or API) and trying to apply them to D1.1. D1.1 does not (with a few specific exceptions) recognize CJP welds welded from one side without backing or backgouging / rewelding. If you intend to backgouge and reweld in production, the welder qualification with backing still qualifies the welder to deposit these welds. Someone please correct me if I am wrong.
I agree with Doug, one test with backing will cover both, provided the weld without backing is backgouged from the second side before welding the second side. IF you need a welder for welding a single sided CJP joint without backing (open root) then that is another matter.
That is it. tthcqci
I'm sorry, but I have to disagree with you gentlemen. I work on the construction of offshore oil platforms, and we use single-sided CJP welds extensively (and I'm not talking about TKYs). Have a look at paragraph 4.26(2), which is for CJP groove welds without backing. It tells you to use the Figure 4.24 test, which is essentially a 6G test. This also gets you qualified for all positions for plate. If you need it for other configurations, the 6GR test also gives you all positions on plate (ref Table 4.9).
If you are strictly interested in an open root qualification for plate, and do not want to do the 6G or 6GR test, you should bring it up with your client. I have been involved in projects where the client accepted open butt plate tests in 3G and 4G to cover all positions for single sided CJP production welds in plate.
Good Morning kipmank,
We were assuming using the prequalifieds, that a groove weld, welded from one side, was not permissible without further testing(WPS and Welder). If access to the second is available for backgouging, then the further testing wouldn't be necessary because he(the welder) would be covered in the one test with a backing strip. If you go by 4.22, Table 4.11 item(6) omission of backing (if tested with backing) requires another test and he was trying to avoid the extra testing. I still wasn't clear if access was availible to the other side of the joint though.
I agree with you 100%. I think in most industries that use D1.1, the need for single-side qualified welders is very limited. The 3G + 4G backing bar tests are sufficient for most situations (ref the second sentence of 4.23).
I also am guilty of making assumptions about the question originally posed. I assumed that he really does need a single-side welder (i.e. no access to back side and use of backing inconvenient or not allowed).
I would agree with kipmank. Tubular connections where access to the backside is not an option and backing is not desired (for what ever reason) is one of the exceptions I was refering to. And it is possible that is the type of weld that the question was asking about. I should have gotten a little more specific. My impression is the D1.1 committee has in mind to either backgouge or use backing where ever practical. If not practical (such as listed above on a tubular connection or a TKY joint), then you have to qualify the welder as referenced in 4.26 as kipmank noted above. If the client wants to accept something other than stated in the code, that is certainly his prerogative also.
I thought the whole intent was to get around qualifying a procedure, and using the prequalifieds would have accomplished this, but 4.12.2 specifically says the CJP Butt joint welded from one side without backing ...WPS shall be qualified and to use Figure 4.24 for that joint without backing and welded from one side.
Anyway, I may have gotten side tracked on the original question with my assumptions, if I did, sorry for the confusion.
edit... I'm all wet, this is all listed under Tubular Connections.(4.12)
I was listening carefully to you guy’s comments. Thank you for the interest. I guess everybody is right concerning the question. My welder really needs to weld plate-to-plate, without backing or back gouging (which is not a WPS's pre-qualified in Fig 3.4 ). I know that this is a rare situation for structural welding. For tubular or box tasks, I have the answer in the code. That is the reason I was considering to use item 4.18.3, which states that the welder that does the procedure qualification test is approved to weld so. If I have only one welder, that is OK to do the complete procedure qualification tests. But if I need more than one welder, my understanding is that I have to qualify the same procedure as many times as the number of welder, which does not sound clever. To solve this question, I am considering now to carry out the test without the backing strip as in my qualified procedure and record this on my welder qualification certs, with the agreement of this approach with the Engineer (based on cl 220.127.116.11, cl 18.104.22.168 and cl 22.214.171.124.
I thank all of you
Americo, Your right on target, except for the last half of your plan. Once your welder has qualified your procedure your good to go. Future welders will simply qualify to that procedure, (easily said). What are your plans for the joint? Process, b.s., b.s..?
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