Performance Requirements for Hose Connection Backflow Preventers (ANSI Approved: 2016)
These devices are designed to be installed on the discharge side of a hose threaded outlet on a potable water system. These two-check devices protect against backflow, due to backsiphonage or low-head backpressure, and are field testable to certify protection under the high-hazard conditions present at a hose threaded outlet. These devicse shall only be used on systems where there is low-head backpressure that does not exceed that generated by an elevated hose equal to or less than 10 feet (3.0 m) in height.
A downloadable version of this standard is also available.