What is an atmospheric vacuum circuit breaker?

Atmospheric vacuum switch (AVB), also called vacuum atmospheric circuit breaker, prevents contaminated water to flow through the water system and contaminate clean water. The valves in the atmospheric vacuum circuit breaker open and close in response to the pressure to guide water to ensure that water flows only in the right direction. Some AVB applications include sprinkler and irrigation systems, commercial dishwashers and hose sockets. The input and outlet are perpendicular to each other, while the valve and the valve seal are located around the input so that it can be sealed if necessary. AVBs are installed in accordance with the water supply line, near the system input control. If the system has multiple input controls, AVB must be installed on each of them. The valve seal is open to allow the system flow. This is because the system has a positive pressure, that is the pressure that forces water in the normal direction of the system for the system.

6 This causes the flow in the water system to be perverted. If there is no valve to prevent backflow, used, contaminated water flows through the system and pollutes clean water supply. However, when an atmospheric vacuum circuit breaker is installed, the negative pressure in the system comes through AVB ventilation and forces a closed valve seal to prevent the flow of contaminated water. The valve also allows air to enter the system and restore the correct pressure.

AVB are simple, inxpensive types of preliminary flow devices, but also have some limitations. The atmospheric vacuum circuit breaker must be installed vertically and at least six inches higher than the water system terminal to function properly. It is also not possible to expose more than 12 hours of constant pressure, otherwise the valve seal can be stuck. Not only does this mean that the system should not run for more than 12 hours at a time, but it also means that no valves can be installed downstream OD AVB, because they are putting pressure on it, even if the system does not run.