Hi everybody
I’m writing all WPSs for a piping project according to ASME B31.3 for a company. There are “A671 Gr. CC60 Class 22” and “A672 Gr. C60 Class 22” materials in the pipes, which their wall thickness is ½ in. (13mm) maximum.
Both of these pipes are P no. 1 and according to ASME B31.3, PWHT is not required for P no. 1 when wall thickness is less than 19mm.
However, the pipes class is 22 and according to ASTM A671 & A672, class 22 means that they have stress relieved after production.
Now I’m in doubt to do PWHT or not. According to ASME B31.3, PWHT is not needed for these pipes because of their wall thickness; but if the pipes do not be stress relieved after welding; their class will change from class 22.