Method for making a joint between a main pipe and a branch pipe and apparatus for use in the method.

摘要

In a method for making a joined pipe, a main pipe is cut so that two V-shaped edges of a right angle are formed in the diametrical positions on the periphery of the main pipe, and a branch pipe is cut so that two peaked edges of a right angle are formed in the diametrical positions on the periphery of the branch pipe. Then, the facets of the V-shaped edges and the peaked edges are fused by heating, and butt-welded under pressure. A heating apparatus includes a heater with a V-shape recessed attachment and a peaked attachment. A cutting apparatus includes a circular rail and a slit inside the circular rail on a base, a clamp for clamping a pipe, and a cutter which moves in the slit. A butt-welding apparatus includes two cradles which can move near to and far from each other, a heater which can position between the two cradles, and a clamp which can rotate on each base.