SAW semi-auto welder qualification

By ctacker (****)

Date 01-09-2008 16:30

I would think if your running SAW you should be looking at fig. 4.22

By motgar

Date 01-09-2008 16:59

Even if the welder is performing semi-auto SAW (hand held)?

By js55

Date 01-09-2008 17:05

I think Fig 4.21 is the appropriate fig. Semi auto SAW does not involve a Welding Operator. It is essentially no different than FCAW or GMAW.

By David Lee (*)

Date 01-09-2008 19:13

Are you sure your asking of the correct figure?
Typically SAW is an automatic process but can be hand held I guess, For automatic it would be fig 4.22.

By js55

Date 01-09-2008 19:32

In this case the SAW is Semi automatic. Its a hand held gun essentially like FCAW and GMAW (a little bigger) only it feeds a pressurized flux as opposed to a gas shielding.
If you take the semi auto gun and mount it on a fixture it now becomes a machine process again. We had a bunch of the semi guns available and did that very thing.
You can do the same with a GMAW or FCAW gun making them machine processes.

By Bill M

Date 01-10-2008 17:39

Motgar has raised a good question-

Say this is a SAW pre-qualified procedure with a backing plate.

If so, doesn't the WPS have to be written using, and in accordance to either prequalified joint detail B-L2a-S, or B-U2-S?

Based on that assumption...wouldn't a 45 deg included angle on the weder qualification test plate exceed the upper limit of the two possible pre-qualified joint details and therefore the test plate as drawn in AWS D1.1 fig 4.21 with the 45 deg included angle- would not be a pre-qualified joint with SAW?

So I think you have to use either adjust the bevel angle to comply with the prequalified joint detail, or see fig 4.22 with the 20 deg included angle for the sub-arc qualification plate since the 20 deg. complies with the pre-qualified joint detail for B-U2-S with SAW. (I would think you might be able to get away with shortening it up a little for the manual hand held sub arc welder qualification test.)

By js55

Date 01-10-2008 18:02

Bill,
Good point. And a clarification seems required.
This seems also to tie into the old argument of whether or not the tolerances of Figs 3.3. and 3.4 are accumulative or not.
So, I would say that if accumulative, you have a possible 20deg that can be added to the 30deg requirement to make a possible 50deg. Problem solved.
If not accumulative as many think, I have always wondered how a fitter should know whether or not the detailer has already taken advantage of the tolerances.
Or is the code expecting fitters to constantly verify detailers by referencing Fig 4.3?
Or, is there no tolerance AT ALL in Figs 4.21 and 4.22?
Interesting that Fig 4.3 would allow +10 and -5 for the prequal but the performance qual Figs would mention nothing of tolerances.
Clearly the code committee did not have Semi Auto SAW in mind.
So, IMO, you either have to qual a procedure to qual your welders, or go with 40deg and request the EOR wave the 5deg. Which is quite reasonable.

By motgar

Date 01-11-2008 14:27

I appreciate the help on this matter.