Defects that occur during steelmaking, rolling of the plate for pipe manufacture and the manufacturing process itself. In principle, all critical defects of this kind should be eliminated in the proof test carried out in the pipe mill.
Pipeline Operators are allowed to repair certain defects, such as, cracks, gouges, hard spots and stress corrosion cracking by grinding them out of the pipe. The grind defect is assessed the same way one would assess external corrosion, assuming the COMPLETE removal of the altered metallurgical area.
