Regarding Thermocouple Number/Locations as per ASME 31.1 2014 Edition

[Rejoy Thomas]

Dear All,

            As we gone through ASME B31.1 2014 edition, it was found that for PWHT refer AWS D10.10. As per AWS D10.10, we need at least 4 thermocouples per joint(minimum), that is 1 for controlling purpose and 3 for monitioring. The monitoring thermocouples need to be attached at Soak Band(SB),HB & GCB respectively for the verification of difference in temperature with respect to the controlling thermocouple. Is it mandatory to attach all these thermocouples during PWHT for ASME S Stamp job/piping? Or is it enough to attach the controlling thermocouple alone to check the soaking temperature, rate of heating/cooling etc. Kindly reply by referring clause.

Thanks & Regards

Rejoy Thomas

STF SpA