Welding up and re-machining an RTJ ring groove

[timsch]

We have some Incoloy 800H RTJ flanges that we typically order without the ring groove to make thermowells with. Our thermowells have a full-penetration weld between the bar and the flange which inputs enough heat to draw in the flange enough that a ring groove (if already present) will pull out of tolerance. We machine the groove into the flange face after the full penetration weld is complete.

We received an order of flanges that already have the groove machined into the face. Is there a prohibition against welding up the groove, welding the thermowell, and then re-machining the groove into the flange?

Our weld procedure for this material does not require PWHT and the filler is ERNiCrMo-3.

 

[gr2vessels]

The code does not prohibit this repair/modification procedure, as long as correct welding procedure is applied and the scope is restauration of the original approved flange profile. It is your reponsibility to ensure that no deformation is inflicted on the repaired/modified part, beyond the allowable tolerances. Remember the re-welding and machining process is always prone to iron contamination, hence you might be looking for trouble with this work.
Simply from code point of view, you can proceed with your proposal.
Cheers,
gr2vessels

 

[timsch]

Thanks for the input. This is the way I viewed the situation as well. Others in my shop had issues with the procedure and stopped the job, but we have proceeded at this time.