DEAR ALL,

Our company has WPS (SA 516 Gr 70 ,60mm thk, smaw +saw)  (impact + pwht) -Qualified for P1G2 to P1G2 , base metal thk 16 to 200 mm (impact) , weld smaw upto   200 mm nd saw upto 200 mm,preheat 100 C, pwht done for 2 hr 15 mins soaking time at 610 C soaking temp.

Now i have same requirement of the job but base metal thk is 40 mm can i use the above WPS, if i go with above wps only problem is soaking time.according to asme sec viii div 1 ucs 56 for 40 mm thk metal pwht time is 96 minutes (minimum).

Second thing can any 1 xplain me below clause with an appropriate example:

QW-407.2 A change in the postweld heat treatment
(see QW-407.1) temperature and time range
The procedure qualification test shall be subjected to
PWHT essentially equivalent to that encountered in the
fabrication of production welds, including at least 80%
of the aggregate times at temperature(s). The PWHT total
time(s) at temperature(s) may be applied in one heating
cycle.