Lap seam cracks

The shell or drum of a boiler in which a lap seam crack is discovered along a longitudinal riveted joint shall be immediately discontinued from use. If the boiler is not more than fifteen years of age, a complete new course of the original thickness may be installed at the discretion of the 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.)