What is the function of a vacuum breaker in plumbing systems?

A vacuum breaker is a crucial device in plumbing systems designed specifically to prevent backflow of contaminated water into the potable water supply. The mechanics of a vacuum breaker use an air inlet valve that opens when negative pressure occurs within the system, effectively breaking the vacuum that can siphon contaminated water back into clean water lines. This function is key for maintaining safe and clean drinking water, especially in systems where water might flow into potentially hazardous sources or where cross-connections could occur.

Understanding this function highlights the importance of installing vacuum breakers in various applications, such as irrigation systems or at hose bibs, where there is a risk of backflow. While regulating water pressure, draining excess water, and avoiding pipe corrosion are important aspects of plumbing, they are not the primary role of a vacuum breaker. Instead, it specifically addresses the crucial need to protect drinking water from contamination due to backflow, making it an essential safety feature in plumbing design.