R stamp requirement?
R stamp requirement?
(OP)
Hi all,
Is R-Stamp required for replacement of a piece of pipe attached to a weldolet? We have a Div.1 pressure vessel with a weldolet on the bottom for drain. We need to replace in-kind the corroded pipe that is welded on the weldolet. Is there any issue with the Code?
Thanks all experts.
Is R-Stamp required for replacement of a piece of pipe attached to a weldolet? We have a Div.1 pressure vessel with a weldolet on the bottom for drain. We need to replace in-kind the corroded pipe that is welded on the weldolet. Is there any issue with the Code?
Thanks all experts.





RE: R stamp requirement?
With that said, I typically require/recommend welding on pressure retaining items and appurtances under Section VIII or Section I to be performed by an R-Certificate holder.
RE: R stamp requirement?
RE: R stamp requirement?
RE: R stamp requirement?
(e) In relation to the geometry of pressure containing parts, the scope of this Division shall include the following:
(1) where external piping; other pressure vessels including heat exchangers; or mechanical devices, such as pumps, mixers, or compressors, are to be connected to the vessel:
(-a) the welding end connection for the first circumferential joint for welded connections;
(-b) the first threaded joint for screwed connections;
(-c) the face of the first flange for bolted, flanged connections;
(-d) the first sealing surface for proprietary connections or fittings;
In my case, I think I will investigate the data book if the drain pipe attached to the weldolet was installed onsite, instead of at the fab shop. I can tell from Para.(e)(1)(a) that replacement of the pipe meets this criteria. The R-stamp will be required?
I forgot to mention it is horizontal vessel, SS material.
RE: R stamp requirement?
RE: R stamp requirement?
RE: R stamp requirement?
RE: R stamp requirement?
These drawings should clearly note the design limits of the vessel and the limits of the piping system.
MJCronin
Sr. Process Engineer
Venture Engineering & Construction
www.VentureEngr.com
RE: R stamp requirement?
This isn't really any different than the use of half-couplings for socket welded connections, whether directly to an extended body valve or to piping. The fillet weld "belongs" to B31.3, along with the valve or piping.
Grinding out the weld and welding in a new piping component can be done by a qualified piping welder without AI involvement. However, you can't go wrong following metenger's recommendaiton of having vessel qualified welders working with an AI do the job.
Do I allow the use of weldolets in my spec's? No. And I severely restrict the use of half couplings. But they are Code legal when done right and for better or for worse, there are enough of them out there that I'll be dealing with them for the rest of my career.
jt