re-PWHT for joint 1

[eegyman5000]

hi,can anyone tell me:
if a heat treated joint is found to be faulty aftr radiography,after removing the discontinuity by grinding
and refilling by welding(only the faulty thickness) should i need to re-PWHT the whole joint even if the repaired thickness is less than 38 mm for P no1 material according to UCS56
THANK YOU

 

[vesselfab]

It all depends on the repair and the reasons for the original PWHT.

If the repair was of small depth (I do not have a code book with me so will go on memory) less than 1/2" (12mm) and the repair was performed with proper preheat and heat maintanence, then it may not have to be pending user and AI approval.

If the vessel was PWHT because of a process reason, it will be up to the USER to approve a repair procedure or to decide if a total local PWHT is in order.

in matters such as this, there are many factors to be considered. Our first action after finding a required repair after PWHT would be to write an NCR and get the AI, USER, and both mechanical & process engineers involved.

If it is a requirement to radiograph seams after PWHT, it is our standard to ultrasonic examine joints prior to PWHT to locate any possible repairs beforehand.

 

[jte]

Good response, vesselfab.

jt