An atmospheric type vacuum breaker is primarily installed to protect against what?

An atmospheric type vacuum breaker is specifically designed to protect against backsiphonage in non-continuous use applications. This type of device operates by allowing air to enter the system when the pressure drops below atmospheric levels, which prevents the possibility of contaminated water being siphoned back into the potable water supply.

When water is not flowing, as in non-continuous use situations, there is a potential for a negative pressure to develop in the piping system, which can create a siphoning effect. The atmospheric vacuum breaker effectively mitigates this risk by breaking the vacuum and allowing air to enter the pipe, thus eliminating the conditions that would lead to backsiphonage.

This distinction is crucial because backsiphonage generally occurs when there is a drop in water pressure, and while continuous use can also present risks, the atmospheric vacuum breaker specifically targets scenarios where water remains stagnant for periods of time, making it a vital component in ensuring the safety and integrity of the water supply in such situations.