Restore Vessel to Service After Overpressure
Restore Vessel to Service After Overpressure
(OP)
I've got a situation in which a 304SST vessel was exposed to a possible overpressure. The vessel is vented, and designed to contain hydrogen deflagrations. In this situation, the vessel may have been exposed to a detonation, exceeding the vessel design by an unknown factor. There is no apparent deformation or damage. I am leaning toward re-hydro to verify strength and tightness, but there are some complication with the hydro and I'd like to hear any opinions on other options. Also, does anyone know of any specific code requirements which would apply? The vessel is ASME U-stamped.





RE: Restore Vessel to Service After Overpressure
what I would do would be to do a full survey.Doa full external and internal visual survey to knock out obvious damage look at the plate not just the welds ,..you dont say what temperature this vessel operates at
Check all cylindrical sections for bulging (strap the section. shine a torch up the sides..very good for detecting bulges)
make a template and check head dome/knuckle radius for deformation...if it hasnt bulged it hasnt yielded...the shell would mostlikely bulge before the head changed shape but you should check anyway.
Check all weld seams and nozzle connections inside and out for cracking use good NDT techniques.it may have stretched elastically and cracked...rather than yielded.
I think I would not hydro..its just had a "hydro" and if it didnt do any damage then its been proven. I would rather do a sensitive leak test , fill it with helium or some such gas and "sniff" all the weld seams
RE: Restore Vessel to Service After Overpressure
RE: Restore Vessel to Service After Overpressure
RE: Restore Vessel to Service After Overpressure
NBIC might have some provisions which would help, but I couldn't find anything specific.
RE: Restore Vessel to Service After Overpressure
My emphasis is more on providing a justifiable techical basis for a recovery proposal. The actual decision on what path to take (inspection, rehydro, replacement, etc.) will be made by our managers, and will certainly involve consulting with the various interested agencies.
I did look through NBIC, but like you I didn't find anything that really seems to apply.