Heat treatment for P-No. 1
Heat treatment for P-No. 1
(OP)
How minimum thickness for P-No. 1 that is required pwht as per Asme B31.3 with the following conditions : 1. performed preheat during welding
2. Preheat does not performed
2. Preheat does not performed





RE: Heat treatment for P-No. 1
For preheat, the nominal thickness is 1" and greater (25 mm), 175 deg F (79 deg C)
For heat treatment, the nominal thickness is greater than 3/4" (20mm). So, you two sets of requirements - one for only preheat and the other for thermal treatment.
You must review ASME B31.1 to understand what nominal thickness means for preheat and thermal treatment.
RE: Heat treatment for P-No. 1