Tests for welds
89.  The seams shall be welded by hammering or rolling the joint. To ensure that the process of welding is satisfactory the scrap ends, or two rings cut from the scrap ends of each tube welded, shall be closed in to one-half the internal diameter of the pipe without fracture of the weld when on the major and minor axis of the closed-in rings respectively. When considered necessary by a surveyor of ships check tensile tests shall be made and the tensile strength across the weld shall not be less than 20 tons per square inch.