The Principle Operation of a Hose Connection Dual Check Valve Vacuum Breaker – Backflow Prevention Device – Installation Considerations

The HCDCV can be installed vertically or horizontally. The HCDCV should not be installed where water discharge would cause damage. The HCDCV has a maximum operating pressure of 125 psi and maximum operating pressure of 180 degrees. Out of the box the first and second check valves are closed and the atmospheric vent is open. The HCDCV can be manually drained to prevent damage from cold temperatures. The center guide check valves are reparable and are manufactured with stainless steel. The HCDCV has a low pressure drop, at 3 gpm the pressure loss is approximately 13 psi. Consult manufacture literature for pressure flow rates. The check valves are spring loaded and will create a pressure loss as a result of the force loading. Backpressure greater than 4.33 psi may cause the check valves to fail allowing non-potable to enter the potable water system. Although the atmospheric vent is open during a backpressure condition, it may not be capable of discharging the total volume of water that is in downstream piping system. Some of the water that is entering the HCDCV during the backpressure condition may enter the potable water system since the atmospheric vent may not be capable of discharging the entire amount. The HCDCV is providing protection. For these reasons, the HCDCV should only be used where backpressure is not an issue and only used for in conjunction with hose connections.