What is an example of a minor hazard backflow prevention device?

A minor hazard backflow prevention device is designed to protect against backflow that could contaminate potable water supplies in scenarios where the potential for contamination is relatively low. The atmospheric vacuum breaker is specifically designed for this purpose. It operates by utilizing atmospheric pressure to prevent backflow and allows air to enter the piping system to avoid suction conditions that could cause contaminated water to be drawn back into the clean water supply.

In contrast, the other devices listed serve different functions and are classified according to the degree of hazard they protect against. The reduced-pressure backflow device and the pressure vacuum breaker are utilized for medium to high hazard situations, while an air gap, although effective, is typically not considered a minor hazard device due to its installation requirements and application in preventing significant backflow risks.