摘要 |
Fitting (1) and pipe line are of polymer material. The fitting has an electric heating element (2) next to the pipe line, and an aperture (3) with indicator peg (4) to indicate the welding process. A recess (5) formed as a ring-shaped channel extends around the aperture. The width of the channel corresponds to at most 20% of the diameter (d) of the aperture. The channel depth (t) is at least 20% and at most 70% of the aperture depth. |