Atmospheric vacuum breaks (AVBs) are common for residential buildings but what about commercial property? Depending on the degree of hazard, a backflow can be chosen for a commercial or agricultural property. In such facilities, there are many different types including;
Reduced Pressure Principle Assemblies – Typically, these will be found in morgues, hospitals, chemical plants, boilers, industrial plants, and more. With two internally loaded check valves that operate independently, there will also be a hydraulically-dependant relief valve between the two.
Double Check Valves – Normally used in non-toxic boilers and elevated tanks, these are mainly produced to protect from back-siphonage, back-pressure, and the resulting low-hazard substances reaching the potable water system. In total, there are two positive-seating check valves fixed as one unit in between two shut-off valves.
Pressure Vacuum Breakers – Finally, the third type that you might find is pressure vacuum breakers and these can be found in laundries, swimming pools, fire sprinkler systems, laboratories, cooling towers, industrial plants, and even lawn sprinkler systems. By utilising a check valve, it has been designed to close (via a spring) when the water stops flowing. If the internal pressure reaches one psi above atmospheric pressure, the air-inlet valve will open and prevent water from entering the potable system.