Georg Fischer Rohrleitungssysteme Ag

Hans W Steinmetz

Dirk Alexander Petry

Alfred Messmer

A shaped part formed as a welding sleeve, consisting of thermoplastic material with a resistance wire winding arranged on its inner circumference, having at least one weld indicator. The indicator consists of a stem which is formed from the material of the body of the shaped part or sleeve. The stem prevents the material which comes under increased pressure upon the welding operation, and is urged towards the surface of the sleeve, from passing into the free space, by the resting against a corresponding surface of the sleeve recess.

Welding sleeve of thermoplastic material with indicator

The welding sleeve has a coil of a resistance wire forming two heating zones and is arranged near the inner circumference of the sleeve. Each heating zone has a region at the beginning and end in which the coil spacing is less than in the center region.

Welding sleeve of thermoplastic material

For welding tubular plastic parts (1) formed as a compound tube there is used a welding element (20) which is arranged with its inner peripheral surface (23) on projections (10) of the tubular parts (1) and reciprocally centers them. The welding element (20) has an annular part (21) with a heating coil (22) on its outer contour. The heating coil (22) has coil strands laid in a zig-zag shape which are curved in a U-shape and extend transversely to the peripheral direction of the annular part (21).

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Schaffhausen, Switzerland

Hans W Steinmetz