Working principle of butterfly valve

Butterfly valve is a valve with disc type opening and closing parts reciprocating 90° or so to open, close or adjust the flow of media. Butterfly valve is not only simple structure, small size, light weight, material consumption, small installation size, small driving torque, easy to operate, fast, and can also have good flow regulation function and closed sealing characteristics, is one of the fastest developing valve varieties in recent decades. Butterfly valves are widely used. The variety and number of its use is still continuing to expand, and to high temperature, high pressure, large caliber, high sealing, long life, excellent regulation characteristics, and a valve multi-functional development. Its reliability and other performance indexes have reached a high level.

The performance of butterfly valves has been improved with the application of chemically resistant synthetic rubber. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, stable size, good resilience, easy to form, low cost, etc., and can be selected according to different requirements of different performance of synthetic rubber, in order to meet the operating conditions of butterfly valve.

Because polytetrafluoron (PTFE) has strong corrosion resistance, stable performance, not easy to aging, low friction coefficient, easy to form, size stability, and can be filled, add appropriate materials to improve its comprehensive performance, get better strength, lower friction coefficient of butterfly valve sealing material, overcome the limitations of synthetic rubber, Therefore, polytetrafluoroethylene as the representative of polymer polymer materials and their filling modified materials, has been widely used in butterfly valve, so that the performance of butterfly valve has been further improved, the manufacture of a wider range of temperature and pressure, reliable sealing performance, longer service life butterfly valve.

In order to meet the requirements of high and low temperature, strong erosion, long life and other industrial applications, the metal seal butterfly valve has been greatly developed. With the application of high temperature, low temperature, strong corrosion resistance, strong erosion resistance and high strength alloy materials in butterfly valve, the metal seal butterfly valve has been widely used in the industrial fields of high and low temperature, strong erosion and long life. Butterfly valve with large diameter (9~750mm), high pressure (42.0MPa) and wide temperature range (-196~606℃) has emerged. So that the butterfly valve technology to a new level.

Butterfly valves have a small flow resistance when fully open. When opened between about 15° and 70°, sensitive flow control can be carried out, so in the field of large diameter regulation, butterfly valve application is very common.

Because of the movement of butterfly valve plate with wipe, so most butterfly valves can be used with suspended solid particles of the medium. Depending on the strength of the seal, it can also be used in powder and granular media.

Butterfly valve for flow regulation. Because the butterfly valve in the pipe pressure loss is relatively large, about three times the gate valve, so in the selection of butterfly valve, should fully consider the pipeline system by pressure loss, should also consider the strength of the butterfly plate under the pipeline medium pressure when closing. In addition, the operating temperature limits of resilient seat materials at high temperatures must be considered.

Butterfly valve structure length and overall height is small, open and close faster, and has good fluid control characteristics. Butterfly valve structure principle is most suitable for the production of large diameter valves. When butterfly valve is required to control flow, the most important thing is to correctly choose the specifications and types of 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, low pressure cut-off (small pressure difference), recommended to choose butterfly valve. Butterfly valve can be used in double adjustment, reducing diameter channel, low noise, cavitation and vaporization phenomenon, a small amount of leakage to the atmosphere, with abrasive medium. Throttling adjustment under special working conditions, or strict sealing requirements, serious wear, low temperature (cryogenic) and other working conditions.