PIPE Russian patent published in 2001 - IPC

FIELD: extrusion devices. SUBSTANCE: pipe is manufactured from several different plastic materials in extrusion device in which high pressure and great mechanical stresses are created in attachment section that is in section of extrusion. Pipe has internal plastic layer, internal electrode layer, insulating layer, and external electrode layer. Internal electrode layer is positioned outside the internal plastic layer. Insulating layer is placed on external side of internal electrode layer. External electrode layer is arranged on external side of insulating layer. Internal plastic layer is manufactured by continuous extrusion method. Insulating layer is made of frothed plastic. Invention makes it possible to detect damage and leakage in main-line pipes and to facilitate their location. EFFECT: improved design. 6 cl, 10 dwg