To provide a synthetic resin pipe joint and a synthetic resin pipe and their coupling structure excellent in fire resistance and sound insulation capable of easily attaching and detaching pipes.
The synthetic resin pipe joint 1 is provided with a water cut-off ring 7 in circumferential direction on the inner peripheral surface of a socket 4 of a synthetic resin made pipe joint 2 on whose outer surface an incombustible layer 3 is provided. The incombustible layer 3 may preferably be inorganic incombustible mortars and may preferably be what a low specific gravity layer 8 and a high specific gravity layer 9 overlie the outer surface of the synthetic resin made pipe joint 2. The synthetic resin pipe 11 has the low specific gravity layer and high specific gravity layer overlying the outer peripheral surface of the synthetic resin made pipe joint. Further, the coupling structure between the synthetic resin pipe joint and the synthetic resin pipe is established by inserting the synthetic resin pipe provided with the incombustible layer on the outer peripheral surface into the socket 4 of the synthetic resin pipe joint provided with the incombustible layer on the outer surface so as to maintain a watertightness with the water cutoff ring 7 provided circumferentially on the inner peripheral surface of the socket 4 of the synthetic resin pipe joint.
TSUNODA YASUSHI
Naotaka Kono
Eiichiro Shimazaki