The Pressure Vacuum Breaker Assembly (PVBA) is an outgrowth of the atmospheric vacuum breaker and evolved in response to a need to have an atmospheric vacuum breaker that could be utilized under constant pressure and was testable.
These assemblies may be used under constant pressure but do not protect against backpressure conditions. The assembly must be at least 12 inches higher than any downstream piping.
A diagram of a pressure vacuum breaker is illustrated below along with typical installation drawings:
|STANDARDIZED INFORMATION FOR PRESSURE VACUUM BREAKERS|
|Installation type:||Above ground|
|Safe to inject chemicals into system?||No|
|Okay to locate control valves downstream?||Yes|
|Okay to locate backpressure source downstream of assembly?||No|
|Installation height in relation to highest downstream piping:||12 inches above ground|
|Number of assemblies required:||One per system|
|Use only with irrigation sprinkler heads?||Yes|
|Testing required after installation:||annually|
|Testing required after repairing or moving assembly?||Yes|