초록 ▼

Backflow prevention is provided in connection with a device having one or more shut-off valves integrated with a double-check-valve backflow prevention device and/or housing. Preferably, a single housing encompasses two backflow preventer check valves, and upstream and downstream shut-off valves. Ty

Backflow prevention is provided in connection with a device having one or more shut-off valves integrated with a double-check-valve backflow prevention device and/or housing. Preferably, a single housing encompasses two backflow preventer check valves, and upstream and downstream shut-off valves. Typically, end users cannot readily remove the shut-off valves (and/or their housing) from the backflow preventer check valves (and/or their housing). No flange or other connection between shut-off valves and backflow preventer check valves (and/or their housing) is required, reducing size, weight and labor requirements. The system can substantially reduce or eliminate potential for installation of double-check-valve backflow preventer devices without shut-off valves.

대표청구항 ▼

1. A double-check-valve backflow preventer apparatus, comprising:first and second backflow prevention check valves; first and second shut-off valves; a housing encompassing said first and second backflow prevention check valves and said first and second manually operable shut-off valves, to define a

1. A double-check-valve backflow preventer apparatus, comprising:first and second backflow prevention check valves; first and second shut-off valves; a housing encompassing said first and second backflow prevention check valves and said first and second manually operable shut-off valves, to define a flow path from an inlet opening of said housing, having an upstream pressure, past said first shut-off valve, past said first check valve, past said second check valve, past said second shut-off valve to an outlet opening of said housing, having a downstream pressure; said check valves being configured to move from an open configuration to a closed configuration if said upstream pressure is not at least a predetermined amount greater than said downstream pressure; said housing being substantially integral wherein a housing portion encompassing at least one of said first and second shut-off valves can not be separated from a housing portion encompassing at least one of said check valves without cutting said housing; a scalable access opening in said housing, different from said inlet and outlet openings, sized and shaped to permit passage of at least one of said first and second check valves therethrough; a cover plate for covering said sealable access opening; and, a flow insert interposed between said cover plate and at least one of said first and second check valves.