A correct Pressure Vacuum Breaker Assembly (PVB) installation is shown below. There shall not be any connections on the service line between the PVB and the water meter. Protective cages are optional and when installed shall meet clearance requirements in addition to providing both side and top access. Cages shall allow for proper drainage and shall retain water. The assembly shall be accessible at all times. The PVB shall be installed outside, above ground, and as close to the water meter as possible.
When backflow occurs, water will exit from the assembly. A PVB may be maintained under pressure by a shut-off valve or valves downstream. But, there shall not be any means whatsoever of imposing pressure by pump or other means. Arizona Water Company only allows this assembly to be installed on single irrigation services.