|
|
Condition |
Reduced Pressure (RP) |
Double
Check (DC) |
Pressure Vacuum Breaker (PVB) |
Atmospheric Vacuum Breaker (AVB) |
Dual
Check (DUC) |
Dual with Atmospheric Port (DCAP) |
|
Continous Pressure |
Y |
Y |
Y |
|
Y |
Y |
|
Possible BackPressure |
Y |
Y |
|
|
Y |
Y |
|
Possible BackSiphonage |
Y |
Y |
Y |
Y |
Y |
Y |
|
Non-Toxic |
Y |
Y |
Y |
Y |
Y |
Y |
|
Toxic |
Y |
|
Y |
Y |
|
|
Most commonly used Anti-Backflow Devices
Reduced Pressure Vacuum Breakers
More Costly than others, but provides superior control under all situations. Slightly more pressure loss as the valve maintains a pressure differential in order to function. Needs to be located outdoors or near a drain. Can be installed in basement.
Double Check Valves
Protects against potentially high health hazards, cannot be used in toxic situations. Suitable for most irrigation needs. Can be installed in basement.
Pressure Vacuum Breakers
Probably the most common form of compliance. Needs to to located outdoors or near a drain. Needs to be installed 15" HIGHER the the highest sprinkler head. Very affordable.