An Atmospheric Vacuum Breaker (AVB) includes which components to function?

• A. Atmospheric vent and check valve
• B. Diaphragm and spring valve
• C. Pilot valve and solenoid
• D. Filter and screen

Answer: (A)

An Atmospheric Vacuum Breaker works by two essential parts that let it break a siphon and stop backflow. The atmospheric vent opens to the air when a vacuum or drop in pressure occurs, allowing air to enter and interrupt the siphoning of water. The check valve then closes to prevent any water from flowing backward toward the potable water supply. Together, they provide a one-way path for water and prevent backflow, which is the core purpose of an AVB.

The other components mentioned don’t achieve this combination. A diaphragm and spring valve describe different valve mechanisms, pilot valve and solenoid relate to automatic control devices, and a filter and screen serve primarily to protect against debris rather than to prevent backflow by venting and one-way flow.