The portable water supply to a urinal equipped with a flushometer valve is protected by which type of backflow device?

The correct choice is the atmospheric type pressure vacuum breaker. This type of device is specifically designed to prevent backflow in applications where a potential for back siphonage exists, such as urinals connected to flushometer valves. In a typical scenario, when water is drawn from the supply for flushing, its rapid flow can create a negative pressure condition, which may lead to back siphonage.

The atmospheric vacuum breaker functions by allowing air into the system if a negative pressure occurs, effectively preventing any contaminants from being drawn back into the potable water supply. This ensures that the urine or any other waste does not mix with the drinking water, maintaining the safety and quality of the water supply.

On the other hand, while reduced pressure zone devices and double check valves also serve to protect against backflow, they are suited for different applications. A reduced pressure zone device is generally used in higher hazard situations where the risk of contamination is more significant. Double check valves are also utilized in certain applications but are not as effective in handling back siphonage as the atmospheric vacuum breaker. A simple check valve, while it can prevent backflow, does not address the specific siphonage risks present in this scenario. Therefore, the atmospheric type pressure vacuum breaker is the