ELECTRIC FUSION COUPLING AND FUSION CONFIRMING METHOD

摘要

PROBLEM TO BE SOLVED: To decide the completion of fusion while preventing the discoloration of a temperature indicating member before the fusion. SOLUTION: On the outer surface of the seat 52 of a saddle 50, an electric fusion coupling, a recess 52a with a specific depth is formed, and an irreversible temperature indicating member 22 which is discolored inducing to the temperature to fuse the saddle correctly is provided in this recess 52a. Since the temperature indicating member 22 is approached to the fusion surface which is the inner surface of the seat 52, a temperature indicating member 22 in which the temperature of discoloration is set much higher can be provided.