| abstract |
A welding joint in which, in a joining portion configured by fitting and insertion of a pipe end portion and a tube end portion, inward expansion and bead formation due to heat welding are suppressed as far as possible or cancelled by further ingenuity of the structure, and which is improved so that welding and integration are satisfactorily enabled without causing a fluid passing resistance, and a method of welding it are provided. n In a synthetic resin-made welding joint that has a pipe end portion 2T into which an end portion 1T of a synthetic resin-made tube 1 is to be fitted and inserted, and that is configured so that the pipe end portion 2T and the tube end portion 1T which is fitted and inserted thereinto are enabled to be welded together by heating of heating means 4 which externally surrounds the pipe end portion 2T, therefore, a synthetic resin-made holder 3 which is fitted and attached onto the pipe end portion 2T is disposed, and a flange 12 for ensuring a radial expansion gap S with respect to the heating means 4 is integrally formed in the holder 3. |