Which type of vacuum breaker is pressure activated?

The pressure-activated vacuum breaker is designed to operate using system pressure to seal off the backflow path. When the pressure in the system reaches a certain level, the internal mechanism of the pressure-type anti siphon vacuum breaker closes, preventing any backflow of contaminants into the potable water supply. This action is crucial in preventing polluted water from entering clean water lines, particularly in residential and commercial plumbing applications.

This type of vacuum breaker is specifically engineered for installations where an air gap or atmospheric pressure needs to be maintained for effective operation. It functions when it detects a drop in pressure that would otherwise allow siphoning, thus engaging to protect the potable water system.

In contrast, the non-pressure type does not rely on the operational pressure of the system to close off the backflow and operates primarily under the principle of atmospheric pressure. The atmospheric vacuum breaker does not have the same sealing capabilities as the pressure-activated version, as it is dependent solely on atmospheric pressure to function.

Additionally, a double check valve provides an entirely different function in backflow prevention compared to any vacuum breaker since it is designed to prevent backflow through a double set of check valves that must be installed in accordance with specific regulations.

Understanding the distinctions between these types is fundamental in ensuring compliance