Lap-Seam Crack: The shell of a pressure vessel, in which a lap-seam crack is

Lap-Seam Crack: The shell of a pressure vessel, in which a lap-seam crack is discovered along a longitudinal riveted joint, shall be immediately discontinued from use. If the equipment is not more than 15 years of age, a complete new course of the original thickness may be installed at the discretion of the inspector and after approval by the Chief Inspector. Patching is prohibited. (By "lap-seam crack" is meant the typical crack frequently found in lap seams, extending parallel to the longitudinal joint and located either between or adjacent to rivet holes.)