ELECTROFUSION OF ELECTROFUSION JOINT, METHOD OF CONFIRMING STATE OF FUSION AND FUSION JOINT SUITABLE FOR USE IN THE METHODS

摘要

The present invention is directed to an electrofusion method in which an electrofusion joint having an electrical heating wire embedded in the inner peripheral region thereof is fitted on or laterally pressed against an end of a resin pipe and electrical current is supplied to the electrical resistance heating wire so as to melt and fuse the electrofusion joint. The joint is beforehand provided with an annular groove formed in the outer peripheral surface of the joint to reach a region near the electrical resistance heating wire. The invention is further directed to a method of confirming the state of fusion of an electrofusion joint in which the joint is beforehand provided with a detection hole formed in the outer peripheral surface of the joint to reach a region near the electrical resistance heating wire. There is also disclosed an electrofusion joint comprising a detection hole formed in the outer peripheral surface of said joint to reach a region near said electrical resistance heating wire, a transparent or translucent heat-resistant lid embedded in or fixed to said joint so as to close said detection hole; and an electrofusion joint having an annular groove formed in the outer peripheral surface of said joint to reach a region near said electrical resistance heating wire, so as to define a pin- or bar-like core, and a stopper member provided above said core and capable of limiting the lift of said core.