Abstract: A plastic pipe (10) includes a pipe body (12), and, at an end of the pipe body (12), there is formed a socket which is provided in the inner surface or in the vicinity of the inner surface thereof with a heat generating unit (18). In coupling, an outer peripheral surface of an end of a pipe (28) to be coupled is scraped by a scraper or the like, and the end is inserted into the socket. Then, an electric current is supplied to the heat generating unit (18) such that a heat is generated by the same. Then, synthetic resin of the coupling surfaces of the pipe (28) and the socket and synthetic resin disposed thereabout are fused, so that the both members are fusion-coupled to each other.

Abstract: An electro-fusion fitting includes a body which is provided with a heater including a magnetic alloy unit having a predetermined Curie temperature in the vicinity of a joint surface thereof in a manner that a surface of the heater is exposed on the joint surface. The joint surface of the body is brought into contact with a joint surface of a member to be coupled and, if a high-frequency current is applied to the magnetic alloy unit by electromagnetic induction, the magnetic alloy unit generates heat, and a temperature of the magnetic alloy unit is kept at the predetermined Curie temperature due to a temperature self-control function thereof. Therefore, if the Curie temperature is set at a fusion temperature, the joint surfaces of the body and the member to be coupled are coupled to each other.