During conventional or uni-directional flushing practices, is the flow from the hydrants measured or controlled?
(A) Most hydrants are of the dry- barrel type; dry-barrel type hydrants must be fully opened while flushing, otherwise the drain hole located at the bottom of the bury (which only seals when the valve is in the full open position) will allow water to escape. During extended operations, if the hydrant valve is in any other position water will flow out of the drain hole with enough force to erode and undermine the area around the hydrant bury. As a result, when using conventional or uni-directional flushing methods, operators are likely turning hydrants to the “full open” position and may not be monitoring or controlling the flows to keep them within or reaching desired flows. The NO-DES unit enables you to precisely adjust the rate of flow with our variable speed pump and flow meter. An attached placard shows the operator exactly what flow rate is needed to achieve the desired 5 ft/sec velocity for each size main to be flushed. This removes any chance of missing the target velocity, and
