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The working principle of butterfly valve

Posted by Bundor valve
The working principle of butterfly valve:
Butterfly valve is a valve that opens and closes according to turn the stem while driving the disc rotation,in the cylindrical channel of the butterfly valve body, the disc type butterfly plate rotates around the axis, mainly rotating the disc plate 90° to do the flow control,the valve is fully open when the disc reaches 90°, and the angle of the disc can be changed to adjust the medium flow rate,generally installed in the diameter direction of the pipe.Butterfly valve and stem have no locking capability,in order to effectively regulate the flow, it is necessary to install the worm gear reducer,the butterfly valve equipped with worm gear reducer not only makes the butterfly valve has the ability of self-locking, but also can change the operating performance of the butterfly valve and adjust the medium flow more accurately.

The characteristics of butterfly valve:
1.The structure is simple,and the boundary dimension is small.Due to its compact structure, the structure length is short,the volume is small and the weight is light, it is suitable for large caliber.
2.When the valve is fully open, the effective flow area of the seat channel is large, so the fluid resistance is small.
3.The opening and closing is convenient and rapid, and the adjusting performance is good.Rotate the butterfly plate 90° to complete the opening and closing.The flow rate can be controlled hierarchically by changing the rotation angle of the butterfly plate.
4.The opening and closing torque is small,since the butterfly plates on both sides of the shaft are basically equal to each other under the action of the medium,the direction of the torque is opposite, so the opening and closing are less force.
5.Low pressure sealing performance is good,sealing surface materials are generally rubber and plastic, so the sealing performance is good.Due to the limitation of sealing ring material, the range of operating pressure and temperature of butterfly valve is small.But the working pressure and working temperature range of hard seal butterfly valve have been greatly improved.
1.Butterfly valve has small flow resistance when fully opened.When the opening is about 15 °~70 °, the sensitive flow control can be performed,so in the field of large caliber regulation, the application of butterfly valve is very common.Due to the movement of the butterfly plate with wipe, so most of the butterfly valve can be used for medium with suspended solid particles.Depending on the strength of the seal, it can also be used in powder and granular medium.
2.Butterfly valves are suitable for flow regulation.Because of the pressure loss of butterfly valve in the pipe is relatively large, it is about three times that of gate valve,therefore, when selecting butterfly valves, full consideration should be given to the influence of pressure loss on the pipeline system, and the strength of butterfly plates to withstand the medium pressure in the pipeline when they are closed.In addition, it is necessary to consider the limit of the operating temperature of the resilient seat material at high temperatures.
3.The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and the valve has good fluid control characteristics.The structure principle of butterfly valve is most suitable for making large diameter valves.When the butterfly valve is required to be used for flow control, the most important thing is to correctly select the specification and type of the butterfly valve so that it can work properly and effectively.