An air-gap device is used to...

An air-gap device is specifically designed to prevent backflow of nonpotable water into a drinking water supply, making it a crucial component in maintaining water safety and public health. The function of this device is to create a physical separation between the water supply and any potential contaminants. This is achieved by ensuring that there is a vertical distance, or "gap," between the inlet of the potable water system and the overflow level of the receiving vessel, which effectively prevents any undesired backflow that could occur due to pressure changes in the water system.

By maintaining this air gap, even if there are fluctuations in pressure that might cause water to flow backward, the physical barrier ensures that nonpotable water cannot contaminate the drinking water supply. Such devices are particularly important in settings where there is a risk of cross-contamination, such as in irrigation systems, industrial applications, or any situation where nonpotable water is present. Therefore, the use of an air-gap device directly supports the safety and integrity of drinking water supplies by eliminating risks associated with backflow.