This 3 inch stainless steel reduced pressure zone backflow preventer assembly is designed to prevent the reverse flow of contaminated water of non-potable quality from being pumped or siphoned into the potable water supply due to backsiphonage and/or backpressure. It is ideal for protection at cross-connections identified as health hazard applications and from other contaminants found at the service line entrance.

This compact and short lay length design features a lightweight 300 Series stainless steel body, domestic non-rising stem resilient seated gate valves, spring-loaded cam-check valves, a pressure differential relief valve, and test cocks.

Flood Detection

• Includes a SentryPlus Alert® flood sensor with technology to detect excessive water discharges from the relief valve.
• When paired with an add-on connection kit, the sensor activates to relay alerts for potential flooding events.
• Connection kit options include BMS, cellular communication, and the Sensor Control Monitor which enables integration with BAS via RS-485 Modbus or the Nexa® platform through Wi-Fi.

Cam-Check Assembly

• Manufactured with thermoplastic construction, stainless steel hinge pins, cam arm, and cam bearing.
• Features a single torsion spring design to minimize pressure drop, providing maximum flow at low pressure drop.
• Modular design with an O-ring seal to the main valve body.

Relief Valve

• Constructed from stainless steel with a balanced rolling diaphragm to eliminate sliding seals and lower maintenance costs.
• Designed for bottom mounting and supplied with a steel reinforced sensing hose.
• Equipped with a sensor on the relief valve for flood detection.

NOTICE: When installing a drain line on the Series 4000SS backflow preventer, use an air gap.