I have a doubt regarding one of our pressure vessel R stamp requirement..The vessel installed on 2010 .Construction code is ASME SEC VIII Div 1 . Now during internal DPT it was found approx. 4 mm (length) crack on the fillet weld Connecting internal vane pack (non pressure part ) support to shell internal cladding (Incoloy 825).The vessel is SA516 mtrl and cladded with Incoloy 825,3 mm. Service is Lethal service. Fillet weld tHroat thickness is 4 mm only. As adviced by our AI we have grinded and removed the crack and inspected by AI. Support plate also Incoloy 825. As per MDR Impact test also exempted.
Now as advised by AI for welding , as it is a lethal service PWHT is mandatory or else alternative to PWHT , we can use welding method 5 as per NBIC. ie..preheat with a minimum 177 deg C.But we don't have qualified WPS for P45 material with preheat temp mentioned above.
Now the doubts are 1) As the defect is on the weld connecting non pressure part to shell internal cladding and as the crack is on the centre of the weld with a length 4 mm.the throet thickness is 4 mm. Also the internal cladding is for corrosion allowance. whether this repair comes out of NBIC. The defect already removed by grinding.
2) For welding PWHT can be waived according to construction code /UCS 56.
Experts please advise .
Now as advised by AI for welding , as it is a lethal service PWHT is mandatory or else alternative to PWHT , we can use welding method 5 as per NBIC. ie..preheat with a minimum 177 deg C.But we don't have qualified WPS for P45 material with preheat temp mentioned above.
Now the doubts are 1) As the defect is on the weld connecting non pressure part to shell internal cladding and as the crack is on the centre of the weld with a length 4 mm.the throet thickness is 4 mm. Also the internal cladding is for corrosion allowance. whether this repair comes out of NBIC. The defect already removed by grinding.
2) For welding PWHT can be waived according to construction code /UCS 56.
Experts please advise .
