| 摘要 |
The invention provides thermally insulated piping comprising: a metal inner tube through which a heated or cooled medium may be passed, the wall of this inner tube exhibiting helical or annular corrugations; an outer tube of plastics material which surrounds the inner tube concentrically but is separated therefrom; and a layer of thermal insulation, composed of a foamed plastics material based on a polyurethane, disposed between the inner and outer tubes; wherein a continuous strip of metal foil is provided between the foam layer and the outer tube or within the wall of this outer tube, this foil being adhesive-bonded at its inner surface and/or at its outer surface to the respective adjoining layer, and the edges of the foil overlapping and being adhesive-bonded to each other. <IMAGE> |
