Patent ID: 9212776
Filing Date: 2015-12-15
Classification: B29C,B29L,F16L,H02M,Y02B

Abstract:
1. A method for installation and repair of insulated piping, wherein the insulated piping comprises an outer pipe made of a weldable polymer material that encases an inner pipe embedded in an insulating layer, and wherein the inner pipe has been substantially exposed over a section between ends of the two outer pipes, the method comprising: placing a sleeve coupling, made of a weldable polymer material incorporating a slit that runs lengthwise along the piping, and whose length exceeds the distance between the outer pipes' ends, over the exposed section of the inner pipe so as to overlap the ends of the outer pipes; and welding the sleeve coupling to the outer pipe at the ends of the outer pipes, by placing an electrically conductive band between the outer pipe and the sleeve coupling, ensuring that free ends of the band project upward through the slit, wherein electric current is connected to the band at the ends brought up through the slit, for a determined period of time, to heat the band and the surrounding polymer material so that they fuse together around the band in order to form a weld joint, and wherein a power converter which has a quasi-resonant converter is employed to produce the electric current that is to be connected to the band, and the quasi-resonant converter comprises a half bridge, a transformer, a choke coil directly connected between the half bridge and the transformer and a pair of an FET driver and an oscillator which is directly connected to the half bridge.