초록 ▼

Multilayer fluid conduits are formed by adhering to a tubular outer surface of a metal pipe, a thermoplastic outer layer. The outer layer permits ends of the multilayer conduit to be joined together in leak-proof fluid conduit systems simply by adhering the conduit ends with compatible thermoplastic

Multilayer fluid conduits are formed by adhering to a tubular outer surface of a metal pipe, a thermoplastic outer layer. The outer layer permits ends of the multilayer conduit to be joined together in leak-proof fluid conduit systems simply by adhering the conduit ends with compatible thermoplastic fittings. For fire protection systems, the preferred metal is steel, the preferred thermoplastic is CPVC and the preferred adhesive is heat activated. The adhesive coated metal pipe is preheated and the CPVC is extruded onto the outer surface of the heated metal pipe. Through the use of fire resistive CPVC, the multilayer conduit systems of the present invention can be installed in more severe fire threat areas than can existing, all plastic piping, including all CPVC piping systems. The conduit is assembled into systems on site simply by cutting and direct bonding with ordinary, all plastic fittings using appropriate bonding agents such as solvent based adhesives. CPVC fittings are preferred for fire protection systems.

대표청구항 ▼

[ We claim:] [1.] A multilayer fluid conduit system comprising:a hollow conduit formed by a hollow length of metal pipe having a pair of opposing open ends defined by a completely closed tubular outer surface, the open ends of the metal pipe defining open ends of the conduit, a layer of thermoplasti

[ We claim:] [1.] A multilayer fluid conduit system comprising:a hollow conduit formed by a hollow length of metal pipe having a pair of opposing open ends defined by a completely closed tubular outer surface, the open ends of the metal pipe defining open ends of the conduit, a layer of thermoplastic completely covering the tubular outer surface of the metal pipe, and an adhesive layer between the metal pipe and the thermoplastic layer distributed to provide a circumferential leak-proof seal between the metal pipe and the thermoplastic layer at least at the open ends of the conduit;a fitting mounted on one open end of the conduit, the fitting including at least one open end receiving and overlapping the one open end of the conduit, the one open end of the fitting having an exposed, innermost tubular surface of thermoplastic directly facing and bonded to the thermoplastic layer on the one open end of the conduit so as to form a leak-proof sealed joint at the one end of the conduit directly between the conduit and the fitting.