ASSE (Plumbing) 1057-2012

The purpose of freeze resistant sanitary yard hydrants is to supply potable water without danger of damage to the device due to freezing, to provide protection of the potable water supply from contamination due to ground water and to prevent backflow in accordance with the backflow prevention device selected. These devices shall only be used on systems where the low-head backpressure does not exceed that generated by an elevated hose equal to or less than 10.0 feet (3.0 m) in height. This device shall not be subjected to continuous pressure.