| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a fire-resistant two-layer pipe which has an inner pipe made of synthetic resin pipe, provided with sound insulation, has inexpensive manufacturing equipment cost, can be easily manufactured, is excellent in fire-resistant property and sound insulation, has no risk of exfoliation and cracking of a mortar layer of an exterior, is inexpensive and, when being used as a drain pipe of high-rise or low-rise building, exhibits superior sound insulation such as diffusion prevention of noise due to shock of water current, etc.SOLUTION: A fire-resistant two-layer pipe is a synthetic resin pipe with the outer surface covered with a fire-resistant sound insulation material of which the inside is a sound-absorbing layer 1 made of nonwoven fabric non-impregnated with mortar, the outside of the sound-absorbing layer 1 being a sound-shielding layer 2 made of nonwoven fabric impregnated with mortar. Therein, a base weight of the nonwoven fabric on an outer surface to be impregnated with mortar is made to be lesser than the base weight of the nonwoven fabric on the inner surface non-impregnated with mortar.</p> |
