Post Weld Heat Treatment

Date 10-15-2005 04:31

Dear Sir,
With all due respect,according to paragraph 331.1.1.b of ASME B31.3, heat treatment to be used after prodution welding,now my question is: if for some reason welding is done after post weld heat treatment is it necessary to cut the joint and then perform post weld heat treatment or only post weld heat treatment is enough?
Best Regards.

By NDTIII

Date 10-15-2005 11:34

If you perform any welding on a joint that has been Post Weld Heat Treated, you must re-perform the Post Weld Heat Treatment again.

By khodabandeh (**)

Date 10-15-2005 13:01

With all due respect,it is not necessary to cut the joint and then re-perform the Post Weld Heat Treatment again???
Best Regards

By QCCWI

Date 10-15-2005 13:47

You only have to perform PWHT agian it would be a waste of time to cut the entire weld out to re-weld it then PWHT agian.

By dragon

Date 10-22-2005 23:30

in my opinion,before PWHT ,you shoud NDT the weld,
NDT the weld again after PWHT.

By George-kh (**)

Date 01-20-2006 05:37

According to ASME B31.3 paragraph 328.6 that is mentioned for repairing: “Preheating and heat treatment shall be as required for the original welding. See also paragraph 341.3.3.”
Therefore, after NDT, which is done after PWHT, if there is a repair, PWHT shall be repeated. You don’t need to cut out the joint. Just do another PWHT on it.