Air gap (plumbing)

For other uses, see Air gap (disambiguation).
Water cannot flow from the sink to the tap in normal circumstances, even if the water supply loses pressure.

An air gap, as related to the plumbing trade, is the unobstructed vertical space between the water outlet and the flood level of a fixture.[1] Air gaps of appropriate design are legally required by water health and safety regulations in many countries. An air gap is the simplest form of a backflow prevention device.

  1. ^ International Residential Code 2003 (1st ed.). Definition: air gap, water–distribution system: International Code Council. 2003. p. 9. ISBN 978-1-892395-58-0.