| 摘要 |
The present invention relates to a method for the installation and repair of insulated piping, wherein the insulated piping comprises an outer pipe 1, 1.1 or 1.2 made of a weldable polymer material that encases an inner pipe 2, 2.1 or 2.2 embedded in an insulating layer 4, and wherein the inner pipe 2, 2.1 and 2.2 has been substantially exposed over a section A between the ends 1 a and 1 b of the two outer pipes. The method comprises placing of a sleeve coupling 7, made of a weldable polymer material incorporating a slit 8 that runs lengthwise along the piping, and whose length 5 exceeds the distance A between the outer pipes' ends 1 a and 1 b, over the exposed section A of the inner pipe 2, or 2.1 and 2.2, and with overlapping of the outer pipes' ends 1 a and 1 b; welding the sleeve coupling 7 to the outer pipes 1, or 1.1 and 1.2, the outer pipes' ends 1 a and 1 b, by placing an electrically conductive band 9 that is pervious to molten plastic between the outer pipe 1, or 1.1 and 1.2, and the sleeve coupling 7, ensuring that the band's free ends 10 project upward through the slit 8; and connecting an electric current to the band 9, to the ends 10 brought up through the slit 8, for a determined period of time, for heating the band 9 and the polymer material surrounded by the band so that they fuse together around the band 9 for formation of a weld joint. The method is characterized by the use of at least one power converter B1 comprising a quasi-resonant converter for producing the electric current that is to be connected to the band 9. In cases when high power output is desired, two series-connected power converters B1 are employed, connected to two different phases and performing summation of the current via the synchronous operation of two quasi-resonant converters B2 for producing the electric current that is to be connected to the band 9. The invention also relates to an apparatus.
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