This air valve is designed for use in water systems to automatically release 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.
Operation
With the pipeline full, under pressure, and with no air present in the valve body, sealing is affected by the combined upthrust of the submerged ball and differential pressure times the orifice area. Accumulating air in the pipeline enters the body. It depresses the water level to the point where the ball mass is sufficient to overcome the differential pressure across the orifice, allowing the ball to drop, opening the orifice and expelling air. When the water level rises as air is discharged, the flotation level of the ball seals the orifice, preventing water loss.
