ASSE (Plumbing) 1020-2004

Pressure vacuum breaker assemblies are for installation in water supply lines to prevent the entrance of non-potable material into the potable water supply by backsiphonage only. It is not for use in any system where backpressure can be applied to the assembly. When a supply pressure is between 7 to 14 kPa (1 to 2 psi), the air inlet valve is open and the assembly will continuously discharge. Due to this probability of water discharge from the atmospheric air inlet valve, the assembly shall only be installed where water discharge does not cause damage.