Abstract: A branch pipe lining method ensures a reliable air-tight connection between a branch pipe liner bag and a fluid pressure sealing nozzle with a simple structure so that the branch pipe liner bag can be inserted into a branch pipe without fail. A branch pipe liner bag impregnated with a hardenable resin and having a flange at one end thereof is used for the branch pipe repair. The flange of the branch pipe liner bag is folded out to be mounted to a fluid pressure sealing nozzle. A close contact between the flange and the fluid pressure sealing nozzle is held by vacuum pressure. The branch pipe liner bag is then everted and inserted from a main pipe into a branch pipe toward the ground by a fluid pressure. The branch pipe liner bag is pressed onto the inner wall of the branch pipe by a fluid pressure, and the hardenable resin impregnated in the branch pipe liner bag is hardened while the bag itself is kept pressed onto the inner wall of the branch pipe.

Abstract: A method for lining a branch pipe comprising the steps of: preparing a tubular liner bag by sewing a rectangular nonwoven resin-absorbent fabric into a tubular shape with one end closed; attaching an impermeable plastic film over the external surface of this tubular liner bag; soaking the nonwoven resin-absorbent fabric with a hardenable fluid resin; everting the liner bag into the branch pipe until the eversion head of the liner bag is stopped by the inner wall of the main pipe; forcing the eversion head of the liner bag to turn downstream in the main pipe, thus allowing the the liner bag to evert entirely; hardening the hardenable fluid resin while inflating the liner bag; and removing that portion of the liner bag which protrudes into the main pipe.