Cover for tube sheet (thick) outlet pipe (thin) PQR?

Thread Content

New member here, I have a question for everyone! ! ! Thank you first. Regarding the welding procedure qualification for flat flanges and nozzles (with bevels), as well as outlet nozzles inserted into the tube sheet (with bevels). How can one conveniently determine the base metal coverage thickness required for the test specimen? For a Φ25x3 pipe inserted into a tube sheet with a thickness of 80 mm (having a groove 7 mm deep), as shown in the diagram, the current situation is as follows: Plant 1 has just been established and the process evaluations are still in progress. If two different process evaluations – one for thicknesses over 38 mm and another for 5 mm (with impact resistance) – are to be used, then at present there are no tube sheets available with a thickness of 38 mm. Such a thick thickness is not needed in actual production either. 2. If evaluated using equal thickness as specified in item 4 of Table 9 of 47014 for butt welds with unequal thicknesses. It is understood that the 6 mm thick test piece covers 80 mm of the base metal, and the weld metal (0–12 mm) covers 7 mm of the butt weld metal. But generally, impact testing is performed on carbon steel and low-alloy steel; the weld coverage should be 6–12 mm. For pipes with a thickness of 3 mm, a 5 mm thick specimen PQR (with impact testing) is used to ensure adequate coverage. Is it okay to do this? . Also, I would like to ask: if I use a 6mm PQR without impact function (for weld thicknesses of 1.5–12), will that be sufficient to address this issue?