AWS D1.1 Procedure Qualification Backing / Backgouging 2

RoboStu · Jul 21, 2014

For a CJP procedure qualification/welder qualification test (3/8" thick, 516 Gr. 70, 1/4" steel backing, FCAW, 3G, E71T-1M, 45° included angle) is it expected per AWS D1.1 (or ASME Sec. IX for that matter) that when a welder uses a backing strip they should not need to backgouge as well?

I have not seen anything that implicitly specifies that backing AND backgouge is not allowed, but it is my opinion/understanding that a good welder should be able to get complete fusion into the backing strip without needing to backgouge after.

I understand "The omission, but not inclusion, of backing or backgouging" is an essential variable per Table 4.5 of AWS D1.1 and
Prequalified WPSs in Clause 3 often have a backing strip OR an open root with a backgouge. AWS D1.1 Sec 5.10.1 on Fusion of backing states: "Groove welds made with the use of steel backing shall have the weld metal thoroughly fused with the backing".

It seems some of the guys here have been qualified at the shipyard before where they were allowed to remove the backing and backgouge. Is this just because of a difference in MIL Specs vs ASME or AWS Code or am I just way off base?

Any clarification would be fantastic. Thanks in advance.

Robo

gtaw · Jul 21, 2014

First point: do not mix procedure qualification with welder performance qualification. They are two separate issue with different requirements. If you are qualifying a welding procedure, only consider the requirements for that effort. Do not even look at performance qualification. Likewise, if you are qualifying the welder, performance qualification, only look at these requirements.

Second point: every welding standard / code has different requirements for procedure qualification and performance qualification. What is done for one code has little it anything to do with another welding standard.

Third point: AWS has no provisions for back gouging the root when qualifying the welder. AWS D1.1 has specific welder performance tests that must be completed. The only test that dos not use backing is the fillet break test and qualifying the welder for open root pipe/tubular connections that have to follow a qualified WPS (qualified by testing per clause 4. A welder that was qualified using a back gouge operation is NOT qualified per AWS D1.1. Once the welder has passed one of the performance qualification test required by AWS D1.1, the contractor can require additional performance testing, i.e., the contractor can require a back gouge operation so the welder can demonstrate proficiency with the grinder or carbon arc gouging equipment (but only after passing the required AWS performance test). The only recognized AWS performance tests are included in D1.1 as figures. If there ain't no figure, it ain't an AWS test.

NAVSEA S9074-AQ-GIB-010/240 also has prescribed tests, but they allow the contractor/employer to use any joint detail included in MIL-STD-22D. Again, a different welding standard with different requirements.

Back to AWS D1.1 - forth point; Clause 5 has nothing to do with procedure qualification or performance qualified. Everything you ever wanted to know about welder performance qualification of procedure qualification is listed in clause 4.

Best regards - Al

RoboStu · Jul 22, 2014

Just the feedback I was looking for.
Thank you gtaw.

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AWS D1.1 Procedure Qualification Backing / Backgouging 2

RoboStu

Nuclear

gtaw

Structural

RoboStu

Nuclear

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