What type of air gap is recommended for a kitchen sink?

• A. AUK3
• B. AUK2 air gap
• C. No air gap
• D. Mechanical backflow device

Answer: (A)

Air gaps prevent backflow by creating a physical air break between the potable water supply and the sink drainage. This break stops contaminated water in the drain from siphoning back into the drinking water, even if pressure in the drain rises or a valve fails.

For a kitchen sink, using a dedicated air gap device that meets code is the preferred method because it provides a reliable, visible, and verifiable separation in the water path. The recommended type in this context is the AUK3 air gap, which is designed to meet typical kitchen backflow protection requirements and is widely approved for these installations. It ensures the required protection is in place and helps guarantee compliance with plumbing codes.

Not using an air gap would leave a path for backflow. A lower-rated air gap might not meet code requirements, offering insufficient protection. A mechanical backflow device is a different approach that protects the supply but does not create the required air gap, and it often involves more maintenance and testing.