Reduced Pressure Zone (RPZ)
Required for high-hazard applications. Provides the highest level of protection with double check valves and an intermediate relief valve. Used where contamination could cause health hazards.
Double Check Valve Assembly (DCVA)
Used for low to moderate hazard applications. Two independently operating check valves in series. Common for fire suppression connections and irrigation.
Pressure Vacuum Breaker (PVB)
Used for irrigation systems and other non-pressurized applications. Prevents back-siphonage but not back-pressure. Must be installed above the highest outlet.
