This design of air valve for use in water systems incorporates both small and large orifices. The small orifice for automatic release of accumulated air during normal operation.Air can enter a pipeline in a number of ways, through pump glands, leaking joints and is even contained in solution in the water itself. This air accumulates at the high points of the system, and unless the flow of water is fast enough to purge the line, large pockets of air form to seriously impede the flow a condition known as “air binding”.
By locating these air valves at specific points in the system, ventilation of these air pockets is achieved, increasing pumping efficiencies and flow capabilities of the pipeline. The large orifice allows automatic ventilation of the pipeline during filling and emptying. When filling, air is exhausted at a sufficiently high capacity to prevent restriction of the filing rate due to built up back pressure. When emptying, air is admitted to the pipeline at a rate sufficient to prevent high vacuum pressures developing.
