초록

A backflow preventer assembly installed between a supply line and a service line, comprising one or more check valves and a high pressure relief valve operating to discharge water in the service line under a high pressure condition.

대표청구항 ▼

[ I claim:] [1.] A backflow preventer assembly comprising:a housing for passage of water between a supply pipe and a service pipe;at least one check valve in said housing;a water heater in fluid communication with said service pipe, said water heater having a pressure relief valve susceptible to fai

[ I claim:] [1.] A backflow preventer assembly comprising:a housing for passage of water between a supply pipe and a service pipe;at least one check valve in said housing;a water heater in fluid communication with said service pipe, said water heater having a pressure relief valve susceptible to failure;a relief valve assembly installed in said housing downstream of said check valve disposed in a reverse flow direction, said relief valve assembly having dimensions sufficiently large enough to empty said service pipe and further having a port open to outside atmosphere and a back-up relief valve operable to open position automatically in response to a predetermined high pressure condition in said service pipe which was not relieved due to a failure of said water heater pressure relief valve, which condition first causes said check valve to close and then causes said back-up relief valve to open, thereby discharging water under high pressure to the outside atmosphere through said port.