WELDING METHOD FOR PIPE CROSS PART

摘要

PURPOSE:To enable automatic welding and to increase the welding efficiency and reliability as well by performing a plane finishing of the branch pipe fitting part of a main pipe more than the outer diameter of the branch pipe and by performing the butt welding of the branch pipe which bevels its tip to a plane finishing part. CONSTITUTION:The fitting part of the branch pipe of a main pipe 1 and the end face at least of the branch pipe 2 are subjected to a plane finishing. A groove is formed by cutting the tip pipe wall of the branch pipe 2 so as to incline for the center. This groove shape is preferably a narrow groove. All periphery weldings are performed centering around the shaft center of the branch pipe 2. In this case the weld line is a circle on the same plane and its groove shape is fixed. The outer periphery of the branch pipe 2 is auxiliarily welded if necessary. The automatic welding is thus enabled because of the groove shape being enabled constant and the weld line being the circle on the same plane as well.