Backflow Prevention Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The atmospheric vacuum breaker is specifically designed to prevent siphonage and backflow in a plumbing system. It works by allowing air into the system when negative pressure occurs, which stops contaminated water from being drawn back into the potable water supply. This action is crucial for maintaining the safety and quality of drinking water by ensuring that harmful substances do not enter the supply due to backflow conditions.

In scenarios where there is a drop in pressure, such as when water is being used elsewhere in the system, the vacuum breaker activates and equalizes the pressure by allowing air to enter. This prevents a vacuum from forming that could siphon potentially contaminated water back into the clean water supply. Thus, the primary purpose of an atmospheric vacuum breaker is to serve as a critical safeguard against contamination, making it an essential component in plumbing systems, particularly in areas where cross-connections might occur.