PWHT, NDT and HT

[Angsi]

Do you,

1. NDT, PWHT and HT or
2. PWHT, NDT and HT or
3. NDT, PWHT, MPI and HT?

Any help will be much appreciated.

Thanks.

 

[weldtek]

To clarify and qualify my comments, I would add, there are many steps that can be taken, over and above those mandated by Code, which constitute good practice. The question I was addressing, (and perhaps I missed the point in the original post), was, is NDE after PWHT a requirement for vessels manufactured from carbon steel, to ASME Sec VIII, Div. 1? I obviously don't believe it is, and Steve and some others think differently. I'm looking forward to Steve's followup because if I'm wrong I want to be corrected. I should add that in looking over UW 11, I did note an instance where UT is requred after PWHT, but it's not likely to affect many fabricators due to the fact that it pertains to single pass welds > 1.5" using the electroslag process. See UW 11 (d)

 

[codeeng]

weldtek
In your case above there is no Code requirement to perform PWHT after heat treatment. However, as I already stated, there are many client specs that do and if so the manufacturer is pretty much obligated to do it before and after in case of repair.

 

[weldtek]

Agreed.

 

[roca]

Most clients / end users request NDT to be performed after PWHT and some also request it to be done before PWHT as well.
In cases where NDT before PWHT is not specified it is up to the fabricator but it would seem prudent to apply NDT before PWHT as an insurance. It is an expensive excercise to repair and re-do a PWHT due to cracks, etc which could have been found before the equipment was put in the furnace.