초록 ▼

A backflow preventer assembly for a liquid supply line includes a single unitary valve body including flanged inlet and outlet end openings and a single access opening generally normal to the flow path defined by the inlet and outlet openings. The body houses a pair of check valve seats on opposite

A backflow preventer assembly for a liquid supply line includes a single unitary valve body including flanged inlet and outlet end openings and a single access opening generally normal to the flow path defined by the inlet and outlet openings. The body houses a pair of check valve seats on opposite sides of the access opening for seating a pair of check valves mounted in series to permit flow from the inlet opening to the outlet opening. Adjustable compression rods interconnecting the two check valves seat the valves against their oppositely facing valve seats. The check valves and compression rods are sized to enable installation and removal of the valves through the access opening. In one embodiment the valve body has a predetermined length for installation in the liquid supply line between a pair of gate valve assemblies, such length being the same as a standard body length for a signel check valve assembly. In a second embodiment, the single unitary body incorporates, in addition to check valve assemblies, a pair of gate valve housings one on each of the opposite sides of the gate valve assemblies so that the single body can incorporate, as a unit, the complete backflow preventer assembly including gate valves and double check valves.

대표청구항 ▼

A valve body for a backflow preventer valve assembly having a pair of check valves arranged in series to permit fluid flow in the same direction, the valve body comprising: a single unitary body member having opposite inlet and outlet end connecting means defining flow inlet and outlet openings, sai

A valve body for a backflow preventer valve assembly having a pair of check valves arranged in series to permit fluid flow in the same direction, the valve body comprising: a single unitary body member having opposite inlet and outlet end connecting means defining flow inlet and outlet openings, said openings defining a common flow axis and said body member defining a generally straight flow path, said body member defining a single access opening between said inlet and outlet end openings, the access opening being generally normal to the flow path, and a pair of annular check valve seats, one on each of opposite sides of said access opening and both closely adjacent to said opening, each of said valve seats defining an annular seat surface in a plane generally normal to the flow path, the annular seat surface of each valve seat of said pair facing the annular seat surface of the other valve seat of the pair, such that a pair of check valve assemblies can be inserted into said valve body through said access opening and urged one against one valve seat surface and the other against the other valve seat surface by a common compression means acting in opposite directions against said valve assemblies, said body member defining a pair of shutoff valve housings, one on each of the opposite sides of said pair of check valve seats.