Patent ID: 6651699
Filing Date: 2003-11-25
Classification: F16L

Abstract:
A liner for a branch pipe of an old repaired pipe lined with a polyethylene liner, said liner comprising:a branch pipe portion made of a tubular body, the branch pipe portion being insertable into an existing branch pipe branching from said old repaired pipe; a welding plate provided at a first end of the branch pipe portion, the welding plate having a top surface to be welded to an inner surface of said polyethylene liner and being formed to have a curvature corresponding the an inner surface of the old repaired pipe; at least one O-ring attached tightly to an outer circumferential surface of a second end of the branch pipe portion; an expandable pressing ring for pressing against an inner surface portion of said second end of the branch pipe portion adjacent to said O-ring to force said O-ring to form a watertight seal against the existing branch pipe; an expanding key for holding the pressing ring in an expanded position to maintain the pressure of the pressing ring against the second end of the branch pipe portion; and a heater laid closely under an upper surface portion of the welding plate, said heater being powered by an external power source so that the upper surface of the welding plate is welded to said inner surface of said polyethylene liner.