METHOD OF MANUFACTURE OF HEATING PIPE FOR PIPELINE, HEATING PIPE FOR PIPELINE AND ITS APPLICATION Russian patent published in 2018 - IPC F16L53/00 B29C47/02 B29C47/06 

FIELD: heating system.

SUBSTANCE: manufacture comprises extruding a two-layer pipe with an electrical insulating inner layer and a first electrically conductive layer. Then, at least two current conductors are spirally wound around the first electrically conductive layer. The first electrically conductive layer with wound current conductors is heated so that it softens on the surface, and the conductors are pressed and closed. Further, by extrusion, a second layer is applied from the electrically conductive moulding material, wherein the thickness of this layer is from 0.1 to 1.5 mm. The current conductors are sealed in such a way that the metal is surrounded and wetted by the melt between the two electrically conductive layers. On top of the layers, an outer shell of electrically insulating plastic material is applied.

EFFECT: effectively prevents the reduction of heating power during the service life.

10 cl, 3 dwg