My question is related with the in-service inspection of pressure vessels. How can we recertify/re-qualify any PV, not knowing its material specification, joint effeciency. No previous inspection record available. Any reference based on NBIC or API-510, please? Only we have existing thickness for shell, dish ends, MAWP and temperature only.

Arif,

No, you cannot recertify a pressure vessel that met Code requirement with unknown material and joint effeciency.

leem817

Dear Leem,
In API-510, which is in-service inspection code, according to cause 7.7, we can evaluate pressure vessels that have no name plate and minimum or no design and construction documentation.
Code suggests to take the stress value of SA-283 Grade C and Joint factor of 0.7. What if stress value of SA-283 is not sufficient enough to get required thickness while vessel is in good condition. Can we cut the sample from the vessel to send to lab for chemical and mechanical test? For RT, we can get 100% to improve joint factor. Please advise.

Gents,

the smartest approach would be to find out the manufacturer of the vessel and contact him for the details of construction.
For a real evaluation, the complete vessel shall be looked at. The NBIC gives some guidance for the inspection and how to proceed. With the complete manufacturers file it will be easy to re-estalish the vessel properties.

If you start making tests of the material, what about the welding material, what about the forming and heat treatment processes.

My best advise: do not sign for something you do not know.

DK

Hi,

To the best of my knowledge:

1. Check your local jurisdiction rules and regulations.
2. NBIC allows to do repair or alteration on unknown material after chemical and mechanical testing of the material subject acceptance by the Inspector and Jurisdiction when required.
3. Both ASME Code and NBIC do not provide rules for re-certification of a pressure vessel. In US those things are not allowed except the vessel Manufacturer can re-stamp the nameplate on an identified vessel.

Thanks,

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AI-OR-US