It's advised that your better, more experienced welder perform a new welding procedure qualification. As gtaw stated, succesfull qualification of the WPS automatically qualifies the welder under ASME IX. Our company primarily used one welder who was qualified for all of our welding processes to...
Whereas the OP has not stated the actual alloys under SB-171 to be welded and I have seen Cu-Ni alloy tubes and auminum bronze tubesheets and other dissimilar Cu alloys used in HX, the seal weld can be problematic. One thing we can all agree is that a mockup is mandated.
You can use TIG or MIG welding processes as long as you have WPS qualified per ASME IX for API 650 monogramed tanks. Best choice will be based on material thckness, distortion concerns and deposition rates. The MIG process will be able to provide much greater deposition rates than TIG even using...
I've never permitted it for either my company welders or welders from other suppliers/contractors under my company's control. For first production weld welder qualification, repairs were made by qualified welders.
If the field contractor has not performed any Code required construction, it might be possible to lure the HRSG manufacturer to supervise the field work under its Quality System and Stamp the final work. If any Code work has been done, as Ed wrote, the installer's work is scrap.
Allowing elements are added from the flux in SMAW welding as well as deoxidizing agents which are propriatary to the manufacturer and greatly influence toughness properties.
Why did you "ask" the vendor (supplier) to impact test at -46 C? If it was in the purchase specifications, the supplier must supply impact testing data meeting minimum specified requirements for the material supplied. Is the minimum design temp -29 C or -46 C? Regardless, the supplier does not...
They are not mandatory under B31.1 and Section I. They can become mandatory based on Customer specifications. During my last few years working after 2010 to 2016, D10.10 was becoming mandatory from a number of customers for local pwht of heavy wall P91 welds.
Contamination in the joint has proved the most likely cause of transverse cracking in carbon steel weldments in my exprience. The 3 equally spaced cracks might indicate contamination from tacking the pipe in place prior to weld completion with a hot crack in the cotaminated area due to welding...
Design temperature and construction code dictate impact testing requirements. If the contents are liquid oxygen, impact testing of the PQR would most likely be required.
