Branch pipe liner bag and branch pipe lining method

Abstract

A branch pipe lining method is provided for maintaining a favorable surface state on the inner surface of a lined branch pipe. The branch pipe lining method utilizes a branch pipe liner bag composed of a tubular resin-absorbent material having a flange formed at one end thereof, wherein the outer surface of the tubular resin-absorbent material is covered with a highly air-tight film, and the tubular resin-absorbent material is impregnated with an unhardened hardenable resin, and a cylindrical fluid pressure sealing member attached to the inner surface of the flange. A cylindrical front end nozzle attached to an opening at one end of a pressure bag is inserting into the fluid pressure sealing member of the branch pipe liner bag, and the front end nozzle and the fluid pressure sealing member are sealed by an elastic member interposed therebetween. Then, a pressurized fluid is supplied into the pressure bag, with the flange of the branch pipe liner bag being in close contact with an opening of a branch pipe, to evert and insert the branch pipe liner bag into the branch pipe from a main pipe toward the ground. The hardenable resin impregnated in the branch pipe liner bag is hardened with the inserted branch pipe liner bag being pressed onto an inner wall of the branch pipe, followed by pulling the front end nozzle out from the fluid pressure sealing member to tear the pressure bag off the branch pipe liner bag.