Whether Grinding or filling is allowed on the Final pass (on capping) for Welder performance qualification test (WPQT) for Plate or Pipe. Since qualification is done based on ASME Sec IX, so need reference only as per ASME Sec IX.
ASME Sec 9 – QW194, which only mentions the Complete joint penetration for visual examination for WPQT. But it is not more specific in case of Grinding or filling and also some other (acceptable limits?) parameters like Reinforcement, undercut, underfill, etc..
Codes do not specify about the grinding & filling, on not only final but even in filler passes. It is the discrepancy of the Inspection authority who witnesses the test. Some allow it while few do not. They feel it is lack of skill on the part of the welder concerned if he is allowed to grind such surface defect.
But, it need not be a fact. Say if it is a surface pore due to sudden breeze or to other reasons where welder is not at fault, he takes the Inspector into confidence to remove such defects by grinding or other means. So it is a selective thinking.
More attention is given in initial visual inspection for root defects like. LP, LF, UC, Ex. Penetration , Oxidation (in TIG process), Cavities, under flush etc., than on surface defects on cap runs.