Working principle of butterfly valve

Butterfly valve is a kind of valve that opens and closes according to the rotating valve stem and drives the disc plate to rotate at the same time. In the cylindrical channel of the butterfly valve body, the disc plate rotates around the axis, mainly rotating the disc plate 90* to do flow control. When the disc plate reaches 90°, the valve is in a fully open state, and the Angle of the disc plate can be changed to adjust the medium flow rate, which is generally installed in the diameter direction of the pipeline. Butterfly valve and valve stem itself is no locking ability, in order to effectively adjust the flow need to install worm gear reducer, the butterfly valve installed worm gear reducer not only makes the butterfly valve self-locking ability, but also can change the operating performance of the butterfly valve and more accurately adjust the medium flow.

Butterfly valve features:

(1) Simple structure, small size. Due to the compact structure, short structure length, small size, light weight, suitable for large caliber.

(2) The fluid resistance is small, when fully opened, the effective flow area of the valve seat channel is large, so the fluid resistance is small.

(3) The opening and closing is convenient and rapid, the adjustment performance is good, and the butterfly plate rotates 90. Both can be completed opening and closing. By changing the rotation Angle of the butterfly plate, the flow rate can be controlled in stages.

(4) The opening and closing torque is small, because the butterfly plate on both sides of the rotating shaft is basically equal to the effect of the medium, and the torque is generated in the opposite direction, so the opening and closing are less labor-saving.

(5) Low pressure sealing performance is good, sealing surface materials are generally rubber, plastic, so the sealing performance is good. Limited by the sealing ring material, the use of the butterfly valve pressure and working temperature range is small. However, the use pressure and working temperature range of the hard-sealed butterfly valve have been greatly improved.

1. When the butterfly valve is fully opened, it has a small flow resistance. When opened between about 15°~70°, sensitive flow control can be carried out, so in the field of large diameter adjustment, the application of butterfly valves is very common. Due to the wipeability of the butterfly plate movement, most butterfly valves can be used in media with suspended solid particles. Depending on the strength of the seal, it can also be used for powder and granular media.

2. Butterfly valve is suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipe is relatively large, about three times that of the gate valve, the influence of the pipeline system by the pressure loss should be fully considered when selecting the butterfly valve, and the strength of the butterfly plate under the pipeline medium pressure should also be considered when it is closed. In addition, the operating temperature limitations of the elastic seat material at high temperatures must be considered.

3. The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. The structure principle of butterfly valve is most suitable for the production of large diameter valves. When butterfly valves are required to be used 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.