Abstract: An anticorrosion sleeve including a resin sleeve and a metal sleeve tightly received in the resin sleeve. The metal sleeve has a gradually expanding outer diameter thereof toward one circular edge thereof in a tapered shape in cross section so that the metal sleeve expands the resin sleeve in diameter when the metal sleeve is inserted into the resin sleeve. The resin sleeve includes a large-diameter portion and a small-diameter portion. The metal sleeve includes an engagement end portion, an intermediate portion, and a tapered end portion in that order. The outer circumference of the engagement end portion of the metal sleeve is engaged beforehand with a step between the inner circumferences of the large-diameter portion and the small-diameter portion of the resin sleeve.

Abstract: A saddle tap to be mounted on a resin pipe, includes a saddle, a branching barrel including a straight piping portion having an internally threaded hole longitudinally extending therealong, and a branch portion extended from the middle of the straight piping portion, the straight piping portion standing at one end thereof on the saddle, a hole-drilling cutter with a rotating tool detachably connected thereto, and having, at one end thereof, a cutting edge integrally formed therewith, the hole-drilling cutter having an externally threaded barrel portion and being screwed into the internally threaded hole of the straight piping portion so that the hole-drilling cutter is longitudinally movable, and a cap detachably mounted on the other end of the straight piping portion of the branching barrel for closing the internally threaded hole.

Abstract: A reliable sleeve unit with a water-absorbing swelling rubber that provides a reliable seal to a branch hole and the branch stop while controlling the development of rust. The rubber layer is applied on a cylindrical metal sleeve having a flange on its outer circumference in a manner such that a certain height length of the metal sleeve from its bottom end face is left uncovered. The height length of the flange is set to be long enough for the flange to be inserted into the inner circumference of the branch pipe to be connected to the branch hole. The rubber layer is applied onto the metal sleeve in a manner such that the height length of the rubber layer coating the metal sleeve is approximately equal to the wall height of the branch hole, or in a manner such that the bottom edge of the rubber layer is set to be higher than the bottom end face of the metal sleeve.

Abstract: A rust-resistant cylindrical metal sleeve for preventing rust and corrosion from developing around the wall of a branch hole when the sleeve is rigidly fitted into a branch hole that is drilled through the wall of a metal conduit such as a water pipeline. The sleeve has a projecting portion on its outer circumference and an inner flange portion inwardly projecting at its lower end. The metal sleeve on its outer circumference is coated with a water-absorbing swelling rubber into which a synthetic resin rubber and a water-absorbing polymer are blended. Preferably, 100 parts by weight of styrene-butadiene rubber or ethylene-propylene-dienemetylene linkage rubber is blended with 10 to 40 parts by weight of the water-absorbing polymer. Since the water-absorbing swelling rubber increases its volume as it absorbs water, pressure in the rubber increases, preventing water ingress through between the metal sleeve and the wall of the branch hole.