An improved method of renewing the damaged ends of boiler tubes

摘要

210,314. Schr÷der, E. March 10, 1923. Tubes.-The ends of boiler tubes, particularly for locomotives, are renewed by cutting off the damaged end, shaping the new end a and the end of a supplementary tube b, fitting them together to form an overlapped joint and then welding by a pair of roller electrodes d, d1 one of which revolves on the outer and the other on the inner circumference of the joint. The overlap may be wide enough to allow two or more annular welds to be made. The joint may be prepared as shown in Figs. 1 or 3, or the tube expanded to form a socket for the renewal piece. In any form the tube a may be shaped to form the spigot and the piece b to form the socket.