| 摘要 |
<p>PURPOSE:To provide a welded joint and a method for connecting the welded joint to a pipe which hold uniformly a gap between the inner surface of a socket and the outer surface of the pipe and prevent the pipe from being drawn off to provide high reliability sealing condition while preventing the pipe from being damaged when the pipe is inserted in the socket. CONSTITUTION:A main electrifying heating element 3 is embedded in the peripheral surface of the central part of a socket in a welded joint and auxiliary electrifying heating elements 5, 6 are embedded in an inlet part and depth part so that heating temperature and heating time can be separately controlled. When the welded joint 1 is connected to the pipe P2, the pipe P2 is inserted in the socket and the auxiliary electrifying heating element 5, 6 are electrified to heat resin the inlet part and depth part of the central part of the socket to the melting temperature or less and expand the resin so that the inner surface of the socket in the central part and the outer surface of the pipe P2 are centered to have a uniform gap (c) therebetween while the pipe P2 is prevented from being drawn out. Next, the main electrifying heating element 3 is electrified for welding and connecting.</p> |
