Patent ID: 6708728
Filing Date: 2004-03-23
Classification: B29C,F16L

Abstract:
A method for trenchless rehabilitation of an existing pipeline by pulling a flexible resin impregnated liner into the existing pipeline from a first access opening to a second access opening and everting a flexible inflation bladder from an eversion access into the pulled in liner to a receiving access to conform the liner to the existing pipeline and curing the resin in the liner, comprising:providing a supply of flexible resin impregnated liner and pulling the leading end of the flexible liner into the pipeline from one of the access openings to the other access opening with the ends of the liner extending beyond the ends of the pipeline into the access openings; providing a supply of flexible inflation bladder and feeding the inflation bladder into the proximal end of the liner in the eversion access; sealingly engaging the inflation bladder in the eversion access to isolate the interior of the inflation bladder; introducing air into the bladder in the eversion access downstream of the sealing engagement of the bladder to force the bladder into the interior of the flexible liner; controlling the speed of eversion of the bladder into the liner by the rate of introduction of air and tension maintained on the bladder until the everting bladder extends to the opposite end of the liner; forming an opening in the bladder in the receiving access while maintaining pressure in the interior of the bladder and allowing air to flow-through the bladder and exit the receiving access; introducing steam into the interior of the bladder at the eversion access downstream from the seal on the bladder and allowing the steam to flow through the bladder and exit through the bladder opening; and allowing the resin in the liner to cure.