This arrangement will prevent any contaminants in the sink from flowing into the potable water system by siphonage and is the least expensive form of backflow prevention. A common use of the term "air gap" in home plumbing refers to a fixture that provides back-flow prevention for an installed dishwasher.
Also, is an air gap required for a dishwasher in Texas?
Texas Plumbing Codes. Texas has adopted two sets of plumbing codes that home and business owners need to abide by, the International Plumbing Code (ICC) and the Uniform Plumbing Code (IAPMO). As an example, in Texas, dishwashers are required to have an 'air gap' that prevents dirty water from flowing back into the unit
Do I have to have the dishwasher vent?
The purpose of an air gap in the dishwasher line is to prevent dirty water from a backed up sink from entering the dishwasher and contaminating your clean dishes. It's a type of vent. All drain lines in the house need some type of vent, and a drain in an island is no exception.
What does an air gap do for a faucet?
An Air Gap faucet requires a larger hole in the countertop than a standard faucet. The “air gap” faucet is a plumbing device designed to provide a siphon break for the drain line of an undersink reverse osmosis unit.