The working principle of butterfly valve

2021-07-28

The butterfly valve is a valve that uses a disc-type opening and closing member to reciprocate about 90° to open, close or adjust the flow of the medium. The butterfly valve is not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, simple and rapid in operation, but also has good flow regulation and closing and sealing characteristics at the same time. It has been developed in the past ten years. One of the fastest valve varieties. The use of butterfly valves is very extensive. The variety and number of its use continues to expand, and it is developing towards high temperature, high pressure, large diameter, high sealing performance, long life, excellent adjustment characteristics, and one valve with multiple functions. Its reliability and other performance indicators have reached a high level.
With the application of chemically resistant synthetic rubber to butterfly valves, the performance of butterfly valves can be improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming, low cost, etc., synthetic rubber with different properties can be selected according to different usage requirements to meet the operating conditions of the butterfly valve.
Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipe is relatively large, about three times that of the gate valve, when selecting the butterfly valve, the influence of the pressure loss of the pipeline system should be fully considered, and the strength of the butterfly plate withstand the pressure of the pipeline medium when it is closed should also be considered. . In addition, it is necessary to consider the limitation of the working temperature that the elastic valve seat material can withstand at high temperatures.
The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. The structure principle of butterfly valve is most suitable for making large-diameter valves. When a butterfly valve is required to control flow, the most important thing is to correctly select the specification and type of the butterfly valve so that it can work properly and effectively.
Generally, in throttling, regulating control and mud media, short structure length, fast opening and closing speed, and low pressure cut-off (small pressure difference) are required. Butterfly valves are recommended. For two-position adjustment, reduced diameter channels, low noise, cavitation and vaporization, a small amount of leakage into the atmosphere, and abrasive media, butterfly valves can be used. Throttle adjustment under special working conditions, or under strict sealing, severe wear, and low temperature (cryogenic) conditions.