Series 009 reduced pressure zone assembly backflow preventers are designed to prevent the reverse flow of polluted water from entering into the potable water supply due to back siphonage and or backpressure. They have a bronze body construction (1/4 to 2 in.) or FDA-approved epoxy-coated cast iron (2 1/2 to 3 in.), two in-line independent check valves, replaceable check seats with an intermediate relief valve, and ball valve test cocks. Series 009 is ideal for the protection of health hazard cross-connections or containment at the service line entrance. Check with local water authorities for installation requirements. The maximum working pressure is 175 psi (12.06 bar).