Air Gaps

An "air gap" is an anti-siphoning device that can be installed on the countertop to prevent the backflow of water in the sink pipes. It is installed in conjunction with dishwashers (and water softeners which are not addressed on our site). The drain hose from the dishwasher goes into the air gap and then into the drain. The air gap must be installed over the flood-rim of the receptacle --i.e. over the sink. If the sink actually did back up, the air gap would prevent "gray water" from going into your dishwasher.

Air gaps come in a variety of finishes to match your plumbing fixtures, hardware or appliances. For a good illustration of air gap installation, link to City of Davis, CA, Planning and Building Dept. Check with your city code to see if it is required--many codes will accept an alternate "loop" method. Many plumbers use this option in which they create a loop in the flexible drain hose and tie it up close to the sink rim behind or on the side of the kitchen sink.