System and device for flushing water mains

摘要

A water distribution system includes flushing hydrants having buried valve assemblies and a removable top stock carried from valve assembly to valve assembly. A vertical marker replaces the top stock when the hydrant is not in use. The buried valve assembly includes a valve urged closed by water pressure and an actuator rod extending through a spider in the top of a vertical barrel. A lock nut on the upper end of the actuator holds the valve closed even if water pressure is lost. The upper end of the vertical barrel includes an internally threaded adapter. The top stock includes a casing which is externally threaded to mate with the adapter and a second rod which is threaded to mate with the actuator rod. The hydrant is assembled by removing the lock nut and screwing the parts together while an operating screw is swung free, then swinging the operating screw into engagement with the second rod. A preferred embodiment permits water samples to be taken from the hydrant. An alternative embodiment provides automatic draining systems to make the hydrant frost proof.