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Let us explain the relationship between the opening degree of a pneumatic ball valve and flow rate

2020-11-16View Original

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What is the relationship between the opening degree of a pneumatic ball valve and flow rate management? This is a question that many of us are interested in knowing, so today Chinese manufacturers will help us understand it together. Pneumatic control ball valves enable proportional regulation; when used in combination with 2/5 way solenoid valves and control boxes, they allow for on/off control. The valve core of the V-type ball valve is designed with a V-shaped notch of specific geometry, giving it precise flow-shutting properties and control capabilities, making it suitable for various control applications. Maximum reliability (safety) of the pneumatic shut-off valve: The valve body is a monolithic structure that is durable and robust; its operation is not affected by pipeline pressure, and leakage of the valve body can be prevented. A pneumatic knife gate valve is a right-angle rotary control valve that is used in conjunction with a valve positioner. The relationship between the opening degree of a pneumatic ball valve and the flow rate data is essentially linear, with the proportion changing continuously. If a company uses such flow rates in its internal control systems, the key characteristics of these flow rates are closely related to the flow resistance of the pipes. For example, even if two pipelines have identical valve sizes and types, differences in the analysis of the risk factors associated with economic losses in those pipelines can result in significant variations in the flow rates through the valves. If a pneumatic ball valve is used in a condition where the throttling degree has a significant impact, the conditions on the back side of the valve disc can lead to cavitation, which may damage the valve; therefore, companies generally use it at an angle of 15° or less. When the pneumatic ball valve is at a medium opening position, the shape of the opening formed between the valve body and the front end of the butterfly plate is centered around the valve shaft; there is no difference in the opening degree on either side. The front end of the butterfly plate on one side moves in the direction of the flow of water, while it moves in the opposite direction on the other side. As a result, one side forms an opening similar to that of a nozzle, while the other side forms an opening similar to that of a throttle hole. The flow velocity is much higher on the nozzle side than on the throttle side, and negative pressure is generated directly beneath the valve on the throttle side, which often leads to the detachment of some rubber seals. The operating torque of rotary butterfly valves varies depending on the degree of opening and the direction in which the valve is opened or closed. For horizontal pneumatic ball valves, especially those with large diameters, the torque generated by the pressure difference between the water above and below the valve shaft, due to the depth of the water flow, cannot be ignored. Generally, large-diameter butterfly valves need to be replaced with pneumatic ball valves, as these latter types offer the advantage of rapid operation and the ability to generate high torque under pressure.

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