How does the design of a pressure vacuum breaker assist in water safety?

The design of a pressure vacuum breaker is specifically intended to enhance water safety by preventing contamination during pressure drops. This device is engineered to maintain a physical barrier against backflow, which can occur when there is a sudden drop in water pressure.

In scenarios where the water system experiences a drop in pressure, potentially caused by firefighting activities or main breaks, contaminated water could be pulled back into the potable water supply. A pressure vacuum breaker mitigates this risk through its mechanism that allows air into the piping system when there is a negative pressure condition. This influx of air prevents any harmful contaminants from being siphoned back into the clean water lines, safeguarding the quality of the drinking water supply.

To better understand the context, while some might consider that storing excess water pressure could be a function of such devices, it is not. Additionally, increasing water flow and eliminating the need for chlorine do not directly relate to the protection against contamination, which remains the pivotal function of a pressure vacuum breaker in a water distribution system.