Minimum Range thickness fow PQR with PWHT

[xuanthien]

Dear Gents,

Refer QW-253 when CVN require, We "change" Holding Time of PWHT is Essential Variable. Refer QW 407.2 i know that maximum holding time of PWHT of WPS = 1.25xPQR.

So How about Minimum Holding time? We afollow record in PQR or follow ASME B31.3, 1 hours/in.