PWHT
PWHT
(OP)
Hi all,
We are going to replace a 3" flange for a vessel (Designed to Sec VIII Div 1). The vessel was PWHT and it was used for steam service. The nozzle thinkness is 0.6". Per UCS 56 SEC VIII Div 1, PWHT is not required for thickness less than 1 1/4". Is PWHT required for this repair?
Thanks,
We are going to replace a 3" flange for a vessel (Designed to Sec VIII Div 1). The vessel was PWHT and it was used for steam service. The nozzle thinkness is 0.6". Per UCS 56 SEC VIII Div 1, PWHT is not required for thickness less than 1 1/4". Is PWHT required for this repair?
Thanks,





RE: PWHT
RE: PWHT
RE: PWHT
(c) for welded joints of all thicknesses if required by UW-2, except postweld heat treatment is not mandatory under the conditions specified below:
(1) for groove welds not over 1⁄2 in. (13 mm) size and fillet welds with a throat not over 1⁄2 in. (13 mm) that attach nozzle connections that have a finished inside diameter not greater than 2 in. (50 mm), provided the connections do not form ligaments that require an increase in shell or head thickness, and preheat to a minimum temperate of 200°F (95°C) is applied;
RE: PWHT
Per UW-2, PWHT is required for vessels used for lethal services. Is steam considered lethal service? I assum the PWHT was done on the vessel at the beginning because of the thickness. If that is the case, I think we don't have to follow Note (c).
RE: PWHT
RE: PWHT
Regards,
Mike
RE: PWHT