This seems a good opportunity to jog a memory, if anyone can help since I don't have any ASME codes handy. There are special exemptions in ASME for WPS's involving low penetrating welds, or tacks. If memory serves it has to do with an HAZ limited to within 1/8" of the surface (even if it is a pressure boundary) or something of that sort. It was intended to simplify the very thing we are talking about here. Name plates , etc. In any case, this could be a very interesting discusssion.
Truthfully, on something like that if you can get by without a recertification I would do it. That's just me, but you know the deal : opinions are like***holes . . . .yadayada
Most coded vessels require all welding to be done by a qualified welder. It does not make any difference if you are welding on a head or tacking on a nameplate. Now the tacker does not have to be qualified the same as the welder welding on the head, but the welder must be tested. That falls under Section IX. Someone welding on a nameplate will need to be qualified to do that job.
BABRT's
Alright..."CERTIFIED VESSEL SHOP"
Sourdough's definition: Anyone who is fully certified, and qualified to make code vessel welds and practices this regularly...................THEN gets greedy and hires a bunch of guys that he "trains" to do "quality" welds in the same shop that he operates. Ultimate outcome, vessels that fail.
The reason I brought that up is that we did literally 10's of thousands of capacitor discharge welds for nameplates and PWHT thermocouples. These welds did not have to be qualified by the standard ASME IX methods, although if other than CD welding the welders certainly did. And even if these welds were performed by another process, if memory it would have made no difference. Iwas hoping someone could clarify the most recent code revisions on this issue.
There is an exemption to the welds you talk about, but I don't think it is a blanket coverage for tack welds. Tack welds have to be performed by a qualified welder, unless you plan on completely removing the tack.
I'm at home today, so I woun't be able to look up the exact wording for what you talk about, but you are correct.
Charles
Thanks Charles. Any additional info would be appreciated. I try to stay in the loop on stuff I used to deal with and don't so much any more. You never know. Besides, it is applicable to this string.
Aw dang it! i figured I'd ruffle some feathers with my last post!