1981 Volume 50 Issue 10 Pages 988-993
In a nuclear power plant, a large number of pieps are set in very complex and narrow places. A remote control pipe welding equipment, in which all welding sequences are controlled by a mini-com-puter, has been developed, in order to solve the difficulty in such narrow place welding. The welding conditions were determined by an experimentally developed algorithm. During the first pass, a torch does not weave, but makes a straight trace along the center line of a groove. It is important to melt an insert ring, but not so much that a concave bead may be formed on the reverse side of the pipe. During the following passes, it is important to make the surface of a bead flat, and neither convex nor undercut at all positions of the pipe. In order to control by a computer, the welding conditions during the first pass and subsequent multi-passes were decided by the welding algorithm. Welding parameters were com-firmed experimentally to give suitable penetration and bead shape.
