Butterfly valve is a kind of valve which is used to open, close or adjust the flow of medium by rotating the 90° of disc type. Butterfly valve Not only simple structure, small size, light weight, the material consumption of the province, the installation of small size, small driving torque, easy to operate, rapid, and can also have a good flow adjustment function and close the sealing characteristics, is the fastest development in the past more than 10 years one of the valve varieties. Butterfly valves are widely used. Its use of varieties and quantities continue to expand, and to high temperature, high pressure, large caliber, high sealing, long life, excellent regulation characteristics, as well as a valve multi-function development. Its reliability and other performance indicators have reached a high level.
With the application of chemical-resistant synthetic rubber in butterfly valves, the performance of the butterfly valve is improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming, low cost and so on, the synthetic rubber with different performance can be selected according to different use requirements to meet the operating condition of butterfly valve.
Because Teflon (PTFE) has strong corrosion resistance, stable performance, not easy to aging, low friction coefficient, easy to shape, stable size, and by filling, adding appropriate materials to improve its comprehensive performance, to obtain better strength, lower friction coefficient of butterfly valve sealing material, to overcome the limitations of synthetic rubber, As a result, the polymer polymeric material and its filler modified material, which is represented by PTFE, have been widely used in butterfly valve, so that the performance of butterfly valve can be further improved, the temperature, pressure range is more wide, the sealing performance is reliable, and the service life is longer than butterfly valve.
The butterfly valve has a small flow resistance when it is fully open. The application of butterfly valve is very common in the field of large aperture regulation when opening between approximately 15°~70° and sensitive flow control.
Because the butterfly valve Butterfly Board movement has the wiping sex, therefore most butterfly valve may use in the suspension solid pellet medium. Depending on the strength of the seal, it can also be used in powdered and granular media.
Butterfly valve is suitable for flow regulation. As the butterfly valve in the tube in the pressure loss is relatively large, about three times times the gate valve, so in the selection of butterfly valve, should fully consider the pipeline system under pressure loss, but also consider the closure of the butterfly plate under the pressure of the pipe medium strength. In addition, consideration must also be given to the limitation of the working temperature of resilient seat materials at elevated temperatures.
The butterfly valve's structure length and the overall height are small, the opening and closing speed is quick, and has the good fluid control characteristic. The structure principle of butterfly valve is most suitable for making large caliber valves. When the butterfly valve is required to be used for flow control, the most important thing is to correctly select the butterfly Valve's specification and type so that it can work properly and effectively.
Usually, in the throttling, regulating control and slurry medium, the requirement of short structure length, fast opening and closing speed, low voltage cut-off (small pressure difference), recommended selection of butterfly valve. The butterfly valve can be selected in the double position adjusting, reducing channel, low noise, cavitation and vaporization phenomenon, leaking to the atmosphere, and abrasive medium. Under special working conditions, throttle regulation, or require strict sealing, wear serious, low temperature (deep cold) and other operating conditions.