PWHT Requirement for stainless steel vessel(Lethal Service)
PWHT Requirement for stainless steel vessel(Lethal Service)
(OP)
Am working on a vessel which falls under lethal service (client's requirement). As per the technical requirement, the vessel should be stress relieved after welding because of lethal service.
The MoC of the vessel is SA 240 TP 316L, Normally SS Vessel will not be PWHT.
Is there is any stipulation to overrule the PWHT requirement
The MoC of the vessel is SA 240 TP 316L, Normally SS Vessel will not be PWHT.
Is there is any stipulation to overrule the PWHT requirement





RE: PWHT Requirement for stainless steel vessel(Lethal Service)
UW-2 states that carbon and low alloy vessels for Lethal Service require PWHT.
You are correct, 316 S/S is not usually subject to PWHT.
Suggest an RFI or Concession Request to your client.
Regards,
Kiwi
RE: PWHT Requirement for stainless steel vessel(Lethal Service)
What technical requirement? The Code is very clear regarding
UW-2.
Low alloy steel is NOT defined as stainless steel in ASME Code space. Look at ASME Section VIII, Div 1, Part C, material classes - Part UCS, UFA (nonferrous), UHA (ultrahigh alloy)...
Review UHA-23 materials.
RE: PWHT Requirement for stainless steel vessel(Lethal Service)