Which feature is an Air Gap?

Which feature is an Air Gap?

• A. A physical separation between the water source and the rim of the tank or container during filling.
• B. A device that vents air into the line.
• C. Two independent check valves with a differential valve.
• D. A chemical additive to prevent contamination.

Answer: (A)

An air gap is a physical space that separates the water source from the fill point, creating an unbroken air barrier between them. This gap prevents backflow because water cannot siphon or be drawn back into the source through a path that includes air—any backflow would have to push through that open air, which doesn’t happen. In practical terms, when filling a tank or container, the fill line should terminate above the rim or maintain a clear air space so contaminated water cannot flow back toward the supply. This is why the described feature fits an air gap: it provides a tangible, atmospheric break in the connection, stopping backflow and protecting the water supply from contamination. Other options describe devices or additives that influence flow or contamination risk, but they do not create that simple physical separation.

An air gap is a physical space that separates the water source from the fill point, creating an unbroken air barrier between them. This gap prevents backflow because water cannot siphon or be drawn back into the source through a path that includes air—any backflow would have to push through that open air, which doesn’t happen. In practical terms, when filling a tank or container, the fill line should terminate above the rim or maintain a clear air space so contaminated water cannot flow back toward the supply.

This is why the described feature fits an air gap: it provides a tangible, atmospheric break in the connection, stopping backflow and protecting the water supply from contamination. Other options describe devices or additives that influence flow or contamination risk, but they do not create that simple physical separation.