PWHT requirement for NACE MR0103

[cmryu]

(Petroleum) 23 Jan 07 18:57
We are reviewing requirement of PWHT related to NACE RP0472 and MR0103 Para4.2

PWHT requirement for clad materials in pressure vessel codes*
; It depends on the thickness and material of base metal. If the head (CS, 60mm thick with 316L SS clad) is one of the pressure vessel parts per ASME, the PWHT for whole vessel is mandatory requirement.
* ASME Sec. VIII, Div.1, UCL-34

However, I would like to confirm how about Carbon Steel material, Is this also comply with clad material.

 

[gr2vessels]

The head has to be PWHT after forming + weld overlay, at some stage, in accordance with UCL-34;-it can be heat treated separatelly or with the whole vessel in one go, dependig on size, furnace size, costs and other fabrication considerations. You could be unlucky to pay for a head delivered PWHT from your supplier and having to do again the PWHT after cladding, to comply with the code.
Your question, however is not quite clear to me, so my answer is:- for the mentioned thickness, the head (C/S with or withot cladding) must be heat treated after forming, particularly if it is made of welded segments.
Please clarify your question, if the answer missed the point.
Cheers,
gr2vessels