Can I do hot work on an internal pipe within a pressure vessel? 1

[GYguy]

A nozzle on a U stamped ASME VIII vessel which has been in service has a internally welded pipe protruding into the vessel. Can this pipe be cut and re welded about 700mm from the vessel wall without affecting the certification on the vessel and requiring a re-test?

Any refernce to the particular section in ASME that relates to this would be appreciated.

 

[Duwe6]

NBIC defines this as a "Repair of a Routine Nature", making the repair need an "R" stamp.

API-510 says "fix it", in the manner it was built, using certified welders working to a qualified WPS

Are vessels under NBIC in your area?

 

[gr2vessels]

The internal pipe beyond the reinforcement limit is not subject of the B&PV code. You can cut and weld, using approved structural welding procedures and appropriate NDE.
Cheers,
gr2vessels

 

[weldtek]

GYguy,
As to your second request regarding a reference in ASME, it would actually be the rules in NBIC that would apply to repair work on an item containing pressure, and in this case, for the reason noted above, those rules don't apply.

 

[bernoullies123]

Not part of ASME-VIII scope. Refer to section U-1.

As far as certification, that would really depend on your regulatory jurisdiction... which in all intense of purposes would generally align with the scope of the code.