Our Air Gap device provides a 3" gap between the water level and your refill water line in order to ensure that cross-contamination and back-siphonage is not possible. The device should be installed outside of the tank either above it or in a separate underground chamber in order for it to function properly. This device meets most plumbing codes that requires an air gap separation between potable and non-potable water lines. The device is typically used in conjunction with a float switch
and a solenoid valve
that control the inlet of back-up supply water.