The biggest difference between the ball valve and the butterfly valve is that the opening and closing of the butterfly valve is a plate, and the ball valve is a ball, the valve and the valve core of the butterfly valve are all revolving around its axis; the valve plate of the gate valve is moving along the axis; the butterfly valve and gate valve can adjust the flow through opening degree; the ball valve is not easy to do. To this point.

Butterfly valve is characterized by fast opening and closing, simple structure, low cost, but tight and pressure bearing capacity is not good. The characteristics of the ball valve are similar to that of the gate valve. However, it is difficult to achieve large caliber due to the limitation of volume and opening and closing resistance.

The butterfly valve's structural principle is especially suitable for making butterfly plates of large caliber butterfly valves installed in the diameter direction of pipes. In the cylindrical passage of the butterfly valve body, the disc shaped butterfly plate rotates around the axis, and the rotation angle is 0 degrees ~90 degrees. When the rotation is 90 degrees, the valve is fully opened. The structure is simple, the cost is low, and the adjustable range is large. Ball valves are usually applied to liquids and gases without particle impurities. They have small pressure loss, good sealing performance and high cost. Comparatively speaking, ball valve seal is better than butterfly valve. The valve seal is pressed on the sphere by the valve seat for a long time. It is faster than the hemispherical valve. The sealing of the ball valve is usually flexible, and it is difficult to use in the high temperature and high pressure pipe. Butterfly valve seal is based on rubber, which is far from the metal seal performance of hemisphere valve, ball valve and gate valve. When the valve is used for a long time, the seat will also produce a trace of wear and tear. It can be used by adjusting the valve stem and filler in the process of opening and closing the valve stem only to rotate 90 degrees. When there is a sign of leakage, a little bolt on the cover of the packing can be pressed to achieve no leakage at the root of the valve, and the valve still is still a small leak. Leakage valve.

In the process of opening and closing, the ball valve operates under the tightening force of the two ends seat. It is larger than the hemispherical valve opening and closing moment. The larger the nominal diameter is, the more obvious the difference of the opening and closing moment is, the opening and closing of the butterfly valve is to overcome the deformation of the rubber, and the torque is greater. The operation time of the gate valve and the cut-off valve is long and hard.

The ball valve and the cock valve are the same type of valve, only its closed part is a ball, the ball round the center line of the body to achieve the opening and closing of a valve. The ball valve is mainly used for cutting, distributing and changing the direction of flow in the pipeline.