Min number of thermocouples for PWHT

[bob74r]

Is there anywhere in any code that actually states the number of thermocouples for PWHT. I know AWS has a "recommended" number but I cant seem to find anywhere that states required. Pipe is built to B31.3.

 

[metengr]

No, this is a process detail. There should be a procedure for PWHT, and this procedure would contain placement of TC's, heating band, sooaking band and the gradient band details on size and location.