Vacuum Breaker Anti Siphon Backflow Preventer 

Brass body

Selection of Vacuum Breakers:

Vacuum breakers are only suitable for scenarios where siphon backflow needs to be prevented.

Atmospheric-type vacuum breakers: They are applicable to locations where no shut-off valves are installed on the downstream pipeline and there is no possibility of back pressure at the outlet. A single-air-inlet type vacuum breaker is recommended.

Pressure-type vacuum breakers: They are suitable for pipelines with shut-off valves installed downstream. An outlet check-type vacuum breaker is recommended, or a combination of a single-air-inlet type vacuum breaker and a check valve on the downstream pipeline can be adopted. For the top of risers, a combined type of single-air-inlet vacuum breaker and air release valve is preferred.

Hose-type vacuum breakers: They are applicable to scenarios where the downstream is specifically connected to a hose and there may be siphon backflow or low-pressure backflow. A check-type vacuum breaker should be selected.

Installation of Vacuum Breakers:

The air inlet of the vacuum breaker should face downward, so it must be installed vertically.

The vacuum breaker should be mounted at the top of the pipeline：

For atmospheric-type vacuum breakers, it should be at least 150mm above the high overflow water level of the outlet.

For pressure-type vacuum breakers, it should be at least 300mm above the high overflow water level of the outlet.

Hose-type vacuum breakers should be installed at a height of over 1000mm from the ground; when used for fixed appliances (such as basins or washing machines), they should be at least 150mm above the appliance’s high overflow water level.

If freezing is possible, a drain valve should be installed at the low point of the water inlet pipe.

When an air release valve is provided, the vacuum breaker should be placed on the lower side of the air release valve.

Reliable floor drainage measures should be in place at the location where the vacuum breaker is installed.