PWHT of CRO
PWHT of CRO
(OP)
I have a project where I have to perform 3 mm of GMAW CRO (ErNiCrMo-3) onto a Vessel that had previously had 3 mm of 316L CRO applied by SAW to a SA516 Gr 70 Vessel. The vessel is ASME VIII Div 2 and also has to conform to NACE for Sour Service. The vessel is in Sour Service and is 2" thick.
Does one have to perform PWHT?
There are 2 questions,
1) What are ASME VIII requirements with the application of CRO onto CRO?
2) Which direction does one take onthe NACE requirements.
Any ideas as to which direction to head would be appreciated.
Thanks
Does one have to perform PWHT?
There are 2 questions,
1) What are ASME VIII requirements with the application of CRO onto CRO?
2) Which direction does one take onthe NACE requirements.
Any ideas as to which direction to head would be appreciated.
Thanks





RE: PWHT of CRO
If you are depositing CRO on top of an existing CRO to build-up the surface, my initial response would be no PWHT is required because you are not contacting the base material directly. If this is the case, I would use elevated preheat.
If you completely remove the original CRO and deposit the overlay directly on the base material, PWHT would be required as per the original weld overlay.
RE: PWHT of CRO
The problem with an elevated Pre-heat is that this work would be done in the field where conditions are difficult as is, adding a pre-heat always complicates matters......
We have in the past done a preheat of 100C on some of our other procedures, whats your thoughts on this?
RE: PWHT of CRO
RE: PWHT of CRO