Vacuum Breaker

General
Chlorination plants according to DIN 19606 are operated under vacuum which is produced by an ejector. The motive water required is supplied either by a boosterpump or by hydraulic pipes. Many plants are switched off simply by interrupting the motive water supply. In this type of plants, often vacuum breakers must be used in order to avoid undesired chlorination.

Use
Vacuum breakers are required if, after switching off the motive water supply, the vacuum exceeds 0.1 bar due to system-related conditions. The vacuum can be caused by a geodetic difference in altitude of the chlorine solution injection point (see installation example) or by a vacuum in the main pipe.

Function
The vacuum breaker is designed like an ejector nonreturn valve. The opening pressure is however just 0.05 bar (compared to 0.1 bar of the ejector nonreturn valve). As a result, the vacuum breaker lets air enter the pipe before chlorine is unintentionally primed.