.18 Lap-Seam Crack.

A. If a boiler or pressure vessel has a lap-seam crack along a longitudinal riveted joint, use of the shell or drum shall be discontinued immediately.

B. If the boiler is not more than 15 years old, a complete new course of the original thickness may be installed upon:

(1) Recommendation by the inspector; and

(2) Approval of the chief boiler inspector.

C. Patching a lap seam crack is prohibited.