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Backflow Protection Program
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Backflow Protection Program

Types of Backflow Devices

Atmospheric Vacuum Breaker (AVB) is a backflow preventer valve that protects against backsiphonage. AVB placement is always downstream of all shut of valves and at least 6 inches above all downstream piping and outlets. Manufacturer design limitations do not allow this valve to operate more than 12-hours in a 24-hour period. Yearly valve testing is not required.

Pressure Vacuum Breaker (PVB) is a backflow preventer valve that protects against backsiphonage. PVB placement must be at least 12 inches above all downstream piping and outlets. Manufacturer design allows for continuous use in a 24-period. Yearly valve testing is required.

Air Gap (AG) is a physical separation of the supply pipe by at least two times the discharge pipe’s diameter (never less than 1 inch) vertically above the overflow rim of the receiving vessel.

Reduced Pressure Valve Assembly (RPZ) is a backflow preventer valve that protects against both backsiphonage and backpressure for pollutants or contaminants. RPZ placement must be between 12 and 36 inches above grade. Installation must allow for accessibility for testing and repair. Yearly valve testing is required.

Double Check Valve Assembly (DCVA) is a backflow preventer valve that protects against both backsiphonage and backpressure for pollutants only. DCVA placement must be between 12 and 36 inches above grade. Installation must allow for accessibility for testing and repair. Yearly valve testing is required.

 

 

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