Branch pipe liner bag and pipe lining method

Abstract

A branch pipe liner bag and a pipe lining method are provided for ensuring to securely joining a flange and a main pipe liner bag to provide a reliable integrated structure. The branch pipe liner bag comprises a tubular resin-absorbent material impregnated with an unhardened hardenable resin. The tubular resin-absorbent material is formed at one end thereof with a rigid flange which is formed with a plurality of bores. In the pipe lining method using the branch pipe liner bag, a portion of unhardened hardenable resin oozing from a main pipe liner bag enters the bores formed through the flange of the branch pipe liner bag and is hardened therein, so that the flange is securely joined with the main pipe liner bag, thereby preventing a gap from being formed therebetween. In addition, the bores may be arranged on concentric circles on the flange, and cords made of a resin-absorbent material may be passed through the bores along the inner or outer periphery of the flange. Since the unhardened hardenable resin is also impregnated into the cords, the flange is more securely joined with the main pipe liner bag. Furthermore, a portion of the main pipe liner bag located on the periphery of a branch pipe opening is protruded due to the cords, so that the protrusion facilitates the positioning of a cutter for accurately cutting a portion of the main pipe liner bag covering the branch pipe opening.