Views: 87 Author: Site Editor Publish Time: 2019-12-25 Origin: Site
The butterfly valve is a rotary valve that is opened and closed by rotating the disc-shaped closing member by 90 ° or about 90 °. The butterfly valve has the advantages of simple structure, light weight, small space occupation, relatively small resistance and rapid opening and closing. At present, the development direction of butterfly valves is mainly towards special conditions such as high temperature, high pressure and low temperature.
The sanitary butterfly valve is a valve that uses a disc-type opening and closing member to revolve around 90 ° to open, close, or adjust the medium flow. 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, easy to operate, and fast, but also has good flow regulating function and closed sealing characteristics. It has been developed into one of the fastest valve varieties recent decades. The variety and quantity of its use continue to expand, and it has developed to high temperature, high pressure, large caliber, high sealing, long life, excellent regulating characteristics, and a valve with multi-function. 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 has improved. Synthetic rubber has the characteristics of corrosion resistance, erosion resistance, stable size, good resilience, easy forming, and low cost. It can also choose synthetic rubber with different properties according to different application requirements to meet the working conditions of butterfly valves.
Because polytetrafluoroethylene has strong corrosion resistance, stable performance, not easy to age, low coefficient of friction, easy to form, and stable in size, and it can improve its comprehensive performance by filling and adding appropriate materials to obtain better strength and friction. The sealing material of butterfly valve with lower coefficient overcomes the limitation of synthetic rubber. Therefore, the polymer materials especially polytetrafluoroethylene and its filling and modification materials have been widely used in butterfly valves, thus making the performance of butterfly valves It has been further improved. Now the butterfly valve with a wider temperature and pressure range, reliable sealing performance and longer service life has been manufactured.
In order to meet the requirements of industrial applications such as high and low temperature, strong erosion, and long life, metal sealed butterfly valves have been greatly developed. With the application of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance, high strength alloy materials in butterfly valves, metal-sealed butterfly valves have been widely used in industrial fields such as high and low temperature, strong erosion, and long life. The butterfly valve with large diameter, high pressure and wide temperature range has appeared, thus bringing the technology of butterfly valve to a whole new level.
The butterfly valve has a smaller flow resistance when fully opened. When the opening is between about 15 ° ~ 70 °, sensitive flow control can be performed. Therefore, butterfly valves are commonly used in the field of large-caliber adjustment .
Due to the wiping action of the butterfly valve butterfly plate, most butterfly valves can be used for media with suspended solid particles. Depending on the strength of the seal, it can also be used for powdery and granular media.
Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipe is relatively large, it is about three times that of the gate valve. Therefore, when choosing a butterfly valve, full consideration should be given to the piping system affected by pressure loss, and the strength of the butterfly plate to withstand the pressure of the pipeline medium when it is closed should also be considered. In addition, the limit of the operating temperature to which the elastic seat material is subjected at high temperatures must also be considered.
The butterfly valve has a small structural length and overall height, a fast opening and closing speed, and good fluid control characteristics. The structural principle of the butterfly valve is suitable for making large-caliber valves. When the butterfly valve is required to be used for controlling the flow, the most important thing is to properly select the size and type of the butterfly valve so that it can work properly and effectively.
Generally, in throttling, regulating control and mud media, if short structure length, fast opening and closing speed and small pressure difference are required, butterfly valve is recommended. Butterfly valves can also be used for double-position adjustment, reduced diameter channels, low noise, cavitation and vaporization, small leakage to the atmosphere, and abrasive media. Butterfly valve is also suitable for throttle adjustment under special working conditions, or strict sealing, severe wear and low temperature conditions.