Structural principle of butterfly valve

Structural principle

 

Butterfly valve is a type of valve that uses a disc type opening and closing element to rotate back and forth about 90 ° to open, close, or regulate medium flow. Butterfly valves not only have simple structure, small volume, light weight, low material consumption, small installation size, small driving torque, simple and fast operation, but also have good flow regulation function and closing sealing characteristics. They are one of the fastest developing valve varieties in the past decade. Butterfly valves are widely used. The variety and quantity of its use are still expanding, and it is developing towards high temperature, high pressure, large diameter, high sealing, long service life, excellent regulation characteristics, and one valve multifunctional. Its reliability and other performance indicators have reached a high level.

 

Working principle

 

Butterfly valves have a small flow resistance when fully opened. When opened between approximately 15 ° to 70 °, it can also perform sensitive flow control, making butterfly valves widely used in the field of large-diameter regulation.

 

Due to the wiping nature of the butterfly valve disc movement, most butterfly valves can be used for media with suspended solid particles. According to the strength of the sealing element, it can also be used for powder and granular media.

 

Butterfly valves are suitable for flow regulation. Due to the large pressure loss of butterfly valves in the pipeline, which is about three times that of gate valves, when selecting butterfly valves, the impact of pressure loss on the pipeline system should be fully considered, and the strength of the butterfly plate to withstand the pressure of the pipeline medium when closed should also be considered. In addition, it is also necessary to consider the limitations of the working temperature that elastic seat materials can withstand at high temperatures.

 

The structural length and overall height of butterfly valves are small, with fast opening and closing speeds, and good fluid control characteristics. The structural principle of butterfly valves is most suitable for making large-diameter valves. When it is required to use butterfly valves for flow control, the most important thing is to correctly select the specifications and types of butterfly valves, so that they can work properly and effectively.

 

Usually, in throttling, regulating control, and mud media, short structural length, fast opening and closing speed, and low pressure cutoff (small pressure difference) are required, and butterfly valves are recommended. Butterfly valves can be used for dual position adjustment, reduced diameter channels, low noise, cavitation and vaporization phenomena, small leakage to the atmosphere, and abrasive media. Under special operating conditions such as throttling adjustment or strict sealing, severe wear, and low temperature (deep cooling) conditions.