LINING METHOD FOR INSTALLED PIPE

摘要

PURPOSE: To improve a method for lining an existing pipe for reducing the diameter of a lining pipe before it is drawn in a buried pipe by drawing the lining pipe into the buried pipe in a dimension smaller than the inner diameter of the buried pipe to heat the same and expanding the lining pipe within the buried pipe by the release of tension. CONSTITUTION: One lining pipe 7 comprising memory holding plastic having an outer diameter larger than the inner diameter of a pipe to be lined is prepared to be heated before taken out of an upsetting die 3 and the partial tension controlling the radial expansion of the outer surface of the lining pipe 7 is applied to the lining pipe by a tensioning device. The outer diameter of the lining pipe 7 is set to a dimension smaller than the inner diameter of a buried pipe 10 and the lining pipe 7 is drawn into the buried pipe in this state. The lining pipe 7 is expanded within the buried pipe by the release of tension. This expansion is brought about by memory under atmospheric pressure at the circumferential temp. of the buried pipe.