scope:

Description

This device is designed to be installed on the discharge side of a hose threaded outlet on a potable water system. This two-check device protects against backflow, due to backsiphonage and low-head backpressure, under the high hazard conditions present at a hose threaded outlet. This device shall only be used on systems where sources of backpressure are not introduced, and the low-head backpressure does not exceed that generated by an elevated hose equal to or less than 3 m (10 ft.) in height. This device shall not be subjected to more than 12 hours of continuous water pressure. A hose connection backflow preventer shall consist of two independent checks, force loaded or biased to a closed position, with an atmospheric vent located between the two check valves, which is force loaded or biased to an open position and a means for attaching a hose.