An older commercial building is undergoing renovations. The existing domestic water supply is connected to a fire suppression system. The Authority Having Jurisdiction (AHJ) requires an appropriate backflow preventer. What type of backflow preventer is typically required for fire suppression systems that contain antifreeze or other non-potable additives?

Question: An older commercial building is undergoing renovations. The existing domestic water supply is connected to a fire suppression system. The Authority Having Jurisdiction (AHJ) requires an appropriate backflow preventer. What type of backflow preventer is typically required for fire suppression systems that contain antifreeze or other non-potable additives?

Answer options:

• Double check valve assembly (DCVA) ✅ Reduced Pressure Principle (RP) assembly
• Pressure vacuum breaker (PVB)
• Atmospheric vacuum breaker (AVB)

Correct answer: Reduced Pressure Principle (RP) assembly

Explanation: For fire suppression systems containing antifreeze or other non-potable additives, the potential for contamination of the potable water supply constitutes a severe hazard. Therefore, a Reduced Pressure Principle (RP) assembly is typically required. An RP device offers the highest level of protection against both backpressure and back-siphonage, making it suitable for severe hazard applications. A DCVA is for moderate hazards, while PVBs and AVBs are for back-siphonage only and are generally for low to moderate hazards.