초록 ▼

For mounting a protective sleeve of plastic over a joint between prefabricated heat insulated pipes, typically subterranean district heating pipes, an axially split plastic sleeve is inserted laterally over the joint so as to bridge the opposed ends of outer protective plastic tubes of the joined pi

For mounting a protective sleeve of plastic over a joint between prefabricated heat insulated pipes, typically subterranean district heating pipes, an axially split plastic sleeve is inserted laterally over the joint so as to bridge the opposed ends of outer protective plastic tubes of the joined pipes. A plastic welding strip provided with a number of embedded parallel heating wires, is placed along and over the relevant annular joint with its opposed ends located spaced from each other adjacent the axial split of the sleeve. The ends of the strip are provided with terminals for parallel connection of the embedded wires, and the wires are electrically heated to weld together the welding strip and the two plastic tube ends. The axial split is then scaled by a similar welding strip.

대표청구항 ▼

A method of joining prefabricated heat insulated pipes having an inner conductor pipe and an outer plastic mantle tube, particularly subterranean district heating pipes, the method comprising the steps of joining ends of the conductor pipes protruding from respective ends of the mantle tube, connect

A method of joining prefabricated heat insulated pipes having an inner conductor pipe and an outer plastic mantle tube, particularly subterranean district heating pipes, the method comprising the steps of joining ends of the conductor pipes protruding from respective ends of the mantle tube, connecting the mantle tubes by an axially slit plastic connector sleeve the respective ends of the mantle tubes substantially flush therewith, providing a plastic welding strip with embedded electrical heating wires, laying each welding strip against an outside of the sleeve end and the respective mantle tube end along an annular joint therebetween with free ends of the welding strip being located mutually spaced and adjacent the axial split, actuating the heating wires for welding the welding strip across the annular joint, and effecting a sealing across both the axial split and a portion of the annular joint remaining between the ends of the welding strips.