Which backflow prevention device is commonly required for protecting drinking water distribution systems from back-siphonage and backpressure?

Which backflow prevention device is commonly required for protecting drinking water distribution systems from back-siphonage and backpressure?

• A. A check valve
• B. Air gap
• C. Double check valve
• D. A reduced pressure principle backflow assembly (RP)

Answer: (D)

Backflow prevention devices are used to stop contaminated water from flowing back into the drinking water system. The device designed to protect against both back-siphonage (low supply pressure) and backpressure (downstream pressure higher than supply) is the reduced pressure principle backflow assembly. It achieves this protection with two check valves and a relief valve that creates and monitors a reduced pressure zone; if pressure on the supply side drops or downstream pressure rises, the relief valve opens to vent, preventing any backflow into the distribution system. Other options either address back-siphonage or backflow under specific conditions but don’t provide this combined, highest level of protection, which is why the reduced pressure principle backflow assembly is commonly required for drinking water systems with higher hazard cross-connections.

Backflow prevention devices are used to stop contaminated water from flowing back into the drinking water system. The device designed to protect against both back-siphonage (low supply pressure) and backpressure (downstream pressure higher than supply) is the reduced pressure principle backflow assembly. It achieves this protection with two check valves and a relief valve that creates and monitors a reduced pressure zone; if pressure on the supply side drops or downstream pressure rises, the relief valve opens to vent, preventing any backflow into the distribution system. Other options either address back-siphonage or backflow under specific conditions but don’t provide this combined, highest level of protection, which is why the reduced pressure principle backflow assembly is commonly required for drinking water systems with higher hazard cross-connections.