What Is the Working Principle of Butterfly Valve?

A butterfly valve is a valve that is opened and closed by rotating the valve stem, while driving the disc to rotate around its axis. In the cylindrical channel of the butterfly valve, the disc-shaped disc mainly performs a 90° rotational motion. When the disc rotates to 90°, the valve is fully opened, and the flow of the medium can be effectively controlled by adjusting the angle of the disc. The butterfly valve is usually installed in the diameter direction of the pipeline, and the butterfly valve and the valve stem itself do not have a locking function. In order to achieve precise flow regulation, a worm gear reducer is usually required. The butterfly valve equipped with a worm gear reducer can not only achieve the self-locking function, but also improve its working performance, making the regulation of the medium flow more accurate.

Features of butterfly valve:

1. Simple structure and small size. Due to its compact structural design, the butterfly valve has a short structural length, small volume and light weight, and is particularly suitable for large diameter pipelines.

2. Low fluid resistance. When the butterfly valve is fully opened, the effective flow area of the valve seat channel is large, so the resistance of the fluid passing through is small.

3. Rapid opening and closing and excellent adjustment performance. The butterfly valve can be opened and closed by rotating the disc plate 90 degrees, and the layered control of the flow rate can be achieved by adjusting the rotation angle of the disc plate.

4. Small switching torque. Since the discs on both sides of the rotating shaft are in opposite directions to the force of the medium, the butterfly valve requires less torque when opening and closing, and the operation is more labor-saving.

5. Good low-pressure sealing performance. The sealing surface material of the butterfly valve is usually made of soft materials such as rubber or plastic, which has good sealing performance. Although the working pressure and working temperature range of the butterfly valve are relatively low due to the limitation of the sealing ring material, the use pressure and working temperature range of the hard-sealed butterfly valve have been significantly improved.

In the fully open state, the flow resistance of the butterfly valve is small. When the opening angle is between 15° and 70°, the butterfly valve can achieve sensitive control of the flow rate. Therefore, the butterfly valve is widely used in the field of large-caliber regulation. Since the movement of the butterfly disc has the wiping nature, most butterfly valves can be used for media containing suspended solid particles. Depending on the strength of the seal, the butterfly valve can also be used for powder and granular media.