PURPOSE: To increase the mechanical strength of a connection part and to enhance the reliability thereof by mounting the first connection part wherein the end surfaces of plastic pipes are welded and the second connection part wherein the outer surfaces of the end parts of the plastic pipes and the inner surface of the socket positioned on said outer surfaces are welded.
CONSTITUTION: The end surfaces of polyethylene pipes 1, 2 are connected by a butt connection part 3 and further connected from the outer peripheries thereof by a polyethylene socket 5 having a hot wire 4. At first, the polyethylene pipes 1, 2 are fixed to the slide members 62, 63 sliding on a base member 61. When the slide members 62, 63 are slid by a hydraulic mechanism, the end surfaces of the polyethylene pipes l, 2 are pressed to a heating plate to be melted and, when said slide members 62, 63 are further slid, the molten end surfaces are mutually welded to form the butt connection part. Thereafter, the lead wires 71, 72 of the hot wire are connected to terminals 73A, 73B to weld the hot wire socket 5 to the outer peripheries of the polyethylene pipes 1, 2. At this time, the outer periphery of the hot wire socket 5 is tightened by a metal band.
SUZUKI TAMIHIKO
KOIZUMI YOSHINOBU
