JPS6430731A - Engineering method for lining pipeline - Google Patents

Abstract

PURPOSE:To compensatingly absorb the difference between the linear expansions of pipeline and of lining and prevent buckling from occurring in the lining and at the same time make it possible to realize the favorable lining at the early stage of the execution by a method wherein a small bore thermoplastic pipe is inserted in a pipeline and heated so as to change the rate of expansion in radial direction alternately and in magnitude in order to cover the plastic pipe wavily onto the inner surface of the pipeline by pressurizing. CONSTITUTION:A plastic pipe 1, the bore of which is smaller than that of a pipeline (a), is inserted in the pipeline (a) and the outer diameter of the pipe 1 is preparatorily expanded at its basic end side to be nearly equal to the inner diameter of the pipeline (a). A heating pig 2, which incorporates an electric heater 2a and is installed in a diametrically expanded part 1a, is conical, for example, and has the maximum outer diameter, which is slightly smaller than the inner diameter of the pipeline, and is equipped with a traction rope on its top side and connecting cords 4 at its basic end side. Further, the plastic pipe 1, which is inserted in the pipeline (a), is internally heated through the travelling of the heating pig 2 in the pipe and at the same time internally pressed by the compressed air fed through a feeding port 7a in the pipe so as to be expanded radially in order to cover the inner surface of the pipeline (a).