Backflow

• Movement of the fluid from downstream to upstream within an installation
• Flow in a direction contrary to the normal or intended direction of flow.
• The unintended flow of water from a potentially polluted source into a potable water supply.

See also Backflow condition

References

1. BS EN 1717 Protection against pollution of potable water in water installations and general requirements of devices to prevent pollution by backflow
2. AS/ NZS 3500.0:2003 Plumbing and Drainage