Backflow Education
Reduced Pressure Zone Assembly (RPZ)
The RPZ (or RP) is used for "High Hazard" applications, as classified by the State of Texas. These types of units are the best mechanical option for preventing backflow occurrances. They are widely used for commercial applications including soda dispensers, ice makers, boilers and any other process that changes the make-up of treated wat
The RPZ (or RP) is used for "High Hazard" applications, as classified by the State of Texas. These types of units are the best mechanical option for preventing backflow occurrances. They are widely used for commercial applications including soda dispensers, ice makers, boilers and any other process that changes the make-up of treated water. They are also used in the residential setting. The most common applications are for swimming pools with an automatic fill valve and on aerobic septic systems.
Pressure Vacuum Breaker (PVB)
The PVB is used in situations that the State of Texas classifies a "Moderate Hazard". They are used in the residential realm quite often, mostly on yard sprinkler systems. They are easily identified by their shape, looking like an upside down "L". They also have uses in commercial applications but companies prefer the higher level of protection provided by the RPZ valve.
Double-Check Valve (DC)
Double-Check Valve (DC)
The Double-Check valve is used for the least hazardous form of backflow situations. The State of Texas allows them to be used for "Low Hazard" applications. Although, several cities and Water Supply Companies (WSC's) have removed the DC valves from their approved assembly lists due to the ineffectiveness of the device. This device is just
The Double-Check valve is used for the least hazardous form of backflow situations. The State of Texas allows them to be used for "Low Hazard" applications. Although, several cities and Water Supply Companies (WSC's) have removed the DC valves from their approved assembly lists due to the ineffectiveness of the device. This device is just what the name says it is. Two "check valves" set in series. The problem with check valves is that they will fail one out of every ten times they operate. (That was from the last study that I have heard of. It could be different now.) The entities that have disallowed them are requiring the PVB to be installed for low and moderate hazard applications. I agree with them!