| 摘要 |
In the body 1 of the welding sleeve there has been embedded an electrical resistance heating wire as the winding 3. The winding 3 is divided into two welding zones 31, which are heated by passage of an electric current, so that they soften and are welded together with connecting pipe unions 23. If a satisfactory weld has occurred, this is indicated by a detector pin 20 placed in a free space 21 of the sleeve body 1, which is lifted by the pressure formed in the welding zones 31 into the position 20'. In this way, one can directly check the formation of a satisfactory joint, without requiring any measurement of the welding time. <IMAGE> |
