Atmospheric Vacuum Breaker (AVB)
An untestable assembly that contains an air inlet valve, a check seat and an air inlet port. It is designed to protect against a non-health and health hazard. This device is to be subjected to normal operating pressure for no more than 12 hours in any 24-hour period.
Backflow Preventer for Pop Carbonator
Per the plumbing code, pop carbonators are to be protected by a vented backflow preventer, such as the one shown to the right.
Pressure Vacuum Breaker (PVB)
A testable assembly containing an independent, internally loaded check valve and an independent, loaded air inlet valve located on the discharge side of the check valve. This assembly is designed to protect against a non-health or health hazard under back-siphon conditions only.