ASME Sect. 1 sequence of RT and PWHT completion
ASME Sect. 1 sequence of RT and PWHT completion
(OP)
Customer has a client that insists the radiography of ASME Sect. 1 header be performed after PWHT. I found nothing in Sect. 1 that states the order these processes must be performed. Logically, we want all welding to be completed prior to performing the PWHT, so RT's are shot and any repairs made prior to PWHT. After PWHT, MT and hydro testing are completed, but not a second RT. Is there a mandatory order (sequence) for completing these processes?





RE: ASME Sect. 1 sequence of RT and PWHT completion
If it is written in eng. specs or any other document between you and your customer than you have to RT after PWHT. If it is not than it is up to you to decide.
RE: ASME Sect. 1 sequence of RT and PWHT completion
RE: ASME Sect. 1 sequence of RT and PWHT completion
So cracking because of PWHT itself is not expected and should never occur.
However, cracks present before PWHT will never go away or become less significant under the motion and stress of heat treatment. Cracks already present will never "fix themselves" or magically re-weld themves during PWHT.
Cracks found by X-Ray or Mag particle exam (or UT or PT) before PWHT will always require reheat, grinding out the indication, re-welding, and a repeat of the PWHT.
So given that, why would you ever go to PWHT without completing NDE?
RE: ASME Sect. 1 sequence of RT and PWHT completion
RE: ASME Sect. 1 sequence of RT and PWHT completion
RE: ASME Sect. 1 sequence of RT and PWHT completion
RE: ASME Sect. 1 sequence of RT and PWHT completion
RE: ASME Sect. 1 sequence of RT and PWHT completion