B31.3 - Post-Weld Heat Treatment

ASME B31.3 provides guidelines for fabricating piping to be used in the process industry. Included in those guidelines are requirements for post-weld heat treatment. Section 331.1.1 of ASME B31.3 provides a range of PWHT temperatures for materials of various P-Number and group numbers. Also included in this section are exemptions to mandatory post-weld heat treatment as well as alterations to the holding time.

 

The requirements apply to all welds of the following P-Number base materials and various material groups. The P-No. that B31.3 provides post-weld heat treatment temperatures for are 1, 3, 4, 5A, 5B, 6, 7, 8, 9A, 9B, 10H 10I, 11A 15E. All other materials use the PWHT specification as required by the WPS.

 

In ProWrite, when creating a WPS from a PQR that specifies Section IX and B31.3 as the applicable code, this minimum PWHT temperature will be determined from the materials being welded and their respective thickness. This required minimum PWHT temperature is shown in the ASME Section IX WPS window and in the printed WPS report.