B-U2-GF D1.1

Date 01-23-2011 13:55

Yes, provided you back gouge the root and have the welder qualify the entire WPS.

AWS D1.1 states that the welders are to be qualified using one of the standard qualification tests listed in the Code.

Read the following clauses found in D1.1-2010. Keep in mind that while the clause number may have changed from previous editions, the verbiage is very similar to earlier editions.

Clause 4.19 "The performance qualification tests required by this code are specifically devised tests to determine a welder's ......"

Clause 4.19.3 "A welder or welding operator may also be qualified by welding a satisfactory WPS qualification plate, pipe, or tubing that meets the requirements of 4.9. The welder or welding operator is thereby qualified in conformance with 4.19.1 and 4.19.2."
Keep in mind that clause 4.9 encompasses all the subordinate clauses delineating the tests and acceptance criteria applicable when qualifying the welder by welding a full blown procedure qualification test plate, pipe or otherwise. VT, NDT (volumetric), guided bend tests, and reduced section tensile tests are required by clause 4.9.

It would seem to me that it is considerably faster and less expensive to test the welder using a standard welder qualification test as depicted in figures 4.21, 4.22 (operator), 4.27, 4.28, or 4.29 (T, Y, or K joints), 4.30, 4.31, 4.32, 4.33, or 4.37. Notice that while these joints may resemble a prequalified joint detail, there are no tolerances assigned to the root opening or the groove angle.

So, while the response to the inquiry is, "Yes you can qualify the welder using the prequalified joint detail B-U2-GF." I would add "if you are crazy!"

I have to ask the question, "Why in the world would you want to force your welder to weld a 30 inch long plate (or longer) and perform all the required NDT and destructive tests required to qualify the WPS when it is easier and faster to have the welder weld a joint as short as 5 inches and pass only the VT and guided bend tests or NDT?"

The mud gets deeper and stickier when you consider the welder qualified with back gouging is only qualified for PJP, CJP that are back gouged, and fillet welds. While the Code states that welders qualified with backing are also qualified for welds that are back gouged, it does not state that welders qualified with back gouging are also qualified for welds made with backing.

Best regards – Al

By greek

Date 01-24-2011 16:35

Thanks for the info looks like figure 4.21 would be the best way

By zzzmbrst (*)

Date 02-03-2011 15:09

Is welding with a backing weld considered a backing?

By welderbrent (*****)

Date 02-03-2011 17:12

Zzz,

WELCOME TO THE AWS WELDING FORUM!!

According to AWS A3.0, 'Backing Weld' is defined as: "Backing in the form of a weld."

So, YES, a backing weld is considered as backing.

In practice, you would then need to clean your joint sufficiently from the opposite side to insure good sound weld deposit with proper joint perameters being met.

Have a Great Day, Brent

By 803056

Date 02-04-2011 04:39 Edited 02-04-2011 04:42

If we are still discussing welder qualification, you can do as you suggest, you are complicating life for yourself and the welder. A backing weld is not a backing bar (as required by the figures depicting the plate tests in clause 4) even though it serves a similar purpose. As previously stated, AWS has prescribed joint details for welder qualification. The alternative to using one of the joint details shown in clause 4 is for each welder to qualify the WPS, i.e., weld a plate that is long enough to perform the requisite 4 guided bend testss, two reduced section tensile tests, as well as VT and volumetric NDT. As a result of each welder qualifying the entire WPS, each welder is qualified within the essential variables of clause 4.

Best regards - Al