The basic principles of cross-connection control are very simple, yet there are thousands of variables that enter the formula in designing and engineering backflow prevention into any potable water system.
Issue: 1/05
Editor's Note: "Back to Basics"
The hydraulic conditions of backpressure and backsiphonage can only cause a problem if there is a passageway from the unwanted material and the drinking water. This passageway is called a cross-connection. There are two types of cross-connections that can be created: either an actual (direct) or potential (indirect) connection. An example of an actual connection would be the feed line from the potable water supply connected to the boiler feed. An example of a potential connection would be a janitorial sink faucet with a hose thread outlet. This has the potential of connecting an open-end hose into the sink of soapy water or dangerous chemicals.