Differences between ball valves and butterfly valves

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The last edit to this post was made by sunjl1981 on 2013-1-7 at 00:20. The biggest difference between the two is that the closing element of a butterfly valve is a plate, while that of a ball valve is a sphere; both the valve plate in a butterfly valve and the valve core in a ball valve rotate around their own axes； The valve disc of a gate valve moves up and down along the axis ； Butterfly valves and gate valves can regulate flow by adjusting the degree of opening ； Ball valves are not suitable for this purpose. Butterfly valves feature fast opening and closing speeds, a simple structure, and low cost, but they have poor sealing performance and pressure resistance. Ball valves share similar characteristics to gate valves, but due to constraints related to size and the force required for opening and closing, it is difficult to create them in large diameters. The structural principle of butterfly valves makes them particularly suitable for manufacturing large-diameter valves; the disc of a butterfly valve is installed in the diameter direction of the pipeline. Within the cylindrical channel of the butterfly valve body, the disc-shaped butterfly plate rotates around its axis by an angle ranging from 0° to 90°; when it reaches 90°, the valve is in its fully open position. It has a simple structure, low cost, and a wide adjustable range. Ball valves are typically suitable for liquids and gases free of particulate impurities; they exhibit low fluid pressure loss and good sealing performance, but are expensive. In comparison, ball valves have better sealing performance than butterfly valves. The sealing of ball valves relies on the valve seat exerting pressure on the ball surface over an extended period; as a result, they wear out more quickly compared to semi-ball valves. Ball valves typically use flexible materials for sealing, which makes them unsuitable for use in high-temperature and high-pressure pipelines. The sealing of butterfly valves relies on rubber as an intermediate element, and its sealing performance, which is based on rubber, differs significantly from the metal-based hard sealing of hemispherical valves, ball valves, and gate valves. After long-term use of a hemispherical valve, slight wear may occur on the valve seat; it can still be used by making adjustments. During operation, the valve stem only needs to rotate 90°. When signs of leakage appear, tightening the bolts on the packing gland slightly will prevent leaks at the packing area. In contrast, with other types of valves, small leaks are tolerated, but when there is significant leakage, the valve must be replaced. During operation, ball valves function under the clamping force of the valve seats at both ends; they require a greater torque to open and close compared to hemispherical valves. The larger the nominal diameter, the more significant this difference in torque becomes. Butterfly valves, on the other hand, need to overcome the deformation of the rubber element in order to open and close, which results in an even higher torque requirement. On the other hand, gate valves and globe valves require a long time to operate and are labor-intensive. Ball valves and plug valves belong to the same type of valve; the only difference is that their closing element is a sphere, which rotates around the axis of the valve body to enable opening and closing. Ball valves are primarily used in pipelines to shut off flow, distribute it, and change the direction of the fluid flow. Source: http://www.hgfcvalves.com/index.php?m=News&a=detail&item=47 # + + .