Backflow prevention devices are implemented to safeguard the public water distribution system from cross-connections. A contemporary community water supply infrastructure is engineered to ensure that water is conveyed to properties and structures under constant pressure. This community water network comprises numerous consumers, where there is a risk to public health if there is a cross-connection between the water supply and a contaminated source.
A cross-connection event can occur when there is a pressure drop in the primary water distribution line. This pressure drop causes a vacuum effect, thus resulting in back siphoning (reverse flow) of potentially contaminated water from end-users into the public water supply.