Circumferential welding AWS D1.1

Date 12-15-2018 15:22 Edited 12-15-2018 17:06

Good morning,
I have a D1.1 question concerning circumferential welding. 9.1 specifically states that clause 9 applies only to tubular connections, so welding solid round parts do not require qualification under clause 9. Does it seem odd that for one to be qualified to weld say a 4” diameter tube or pipe they need to qualify on tube, but if they weld a 4” diameter solid a qualification on plate is all that they need? What if that 4” solid had a ¼” hole drilled through it, would the welder and procedure then need to be qualified by clause 9? I’m not an engineer and I do realize that clause 9 does have a lot of design considerations in it, but part of the requirement of testing on pipe is due to the difficulty of welding around in a circle. That welder difficulty is obviously a concern of the code due to the restrictions on diameter sizes qualified for in clause 9. Whether or not the part is solid or hollow makes no difference on the skill required to weld around the circumference of it. I am curious why this type of scenario is not addressed in clause 4. Does anyone have any thoughts on this?
Thanks

By Steelslinger (**)

Date 12-17-2018 21:18

I believe a lot of it has to do with, not so much that it is round (remember Clause 9 also encompasses box tube), but that tubing presents differences in relation to groove welds and the joint configuration limitations/requirements of such.

We do a lot of box tubing welds here, the biggest issue that I see in the different approaches is that to do a CJP weld in tubing, you have to use a backer, or be qualified in open root CJPs. As for solid round bar, I can prepare a bevel in such a way that it would mimic a groove weld in thick plate, as well as backgouge it and not have to weld in a circle. Can't backgouge with tubing, box or round, normally .

As to you're example of a 4" solid round with a 1/4" hole drilled though the center, some could make a case that that is now a HSS and would need to be qualified via Clause 9. Unlikely, but possible.