If you are using ASME Sec IX, No. QW 403.11 is the only restriction.
Below are the essential variables from QW 235
403.7 T/tLimits > 8 in. (203 mm) X
403.8 f TQualified X
403.9 tPass > 1⁄2 in. (13 mm) X
403.11 f P-No. qualified X
403.13 f P-No. 5/9/10 X
Let us know if you are using a different code.
Have a good day
Gerald Austin
Other Welding related info at http://www.weldinginspectionsvcs.com/miscpages.htm
Iuka Ms.
Yes, you may directly revise the AWS No. in your old WPS, or you can use the existing PQR to write a new WPS. For P-8 to P-8 welding, usually you should pay attention to the changed in filler metal A-No., then you are ok in most of the time, if there is no essential varibles changed.
Kind