Working Principle of Butterfly Valve

Butterfly valve is a kind of valve that is opened and closed according to the rotation of the valve stem to drive the disc to rotate. In the cylindrical passage of the valve body, the disc is rotated around the axis to control the flow rate. When the disc is rotated a quarter turn, the valve is fully open. And the angle of the disc can be changed to adjust medium flow. Butterfly valve and the stem do not have self-locking capability. In order to effectively regulate the flow, worm gear reducer must be installed, which not only enables butterfly valve to have self-locking capability, but also can change its operation and regulate the medium flow more accurately.
 

1. Butterfly valve has small flow resistance when fully opened. Sensitive flow control can be carried out when the opening is between about 15 and 70 degrees. Thus, butterfly valves are widely used for large-caliber regulation. The disc moves with wiping performance so that most butterfly valves can be used for medium with suspended solid particles. And the valve can also be used for powdery and granular media, depending on the strength of the seal. 

2. Butterfly valves are suitable for flow regulation. Due to the relatively large pressure loss of butterfly valve in the pipe — Its pressure loss is about three times that of gate valve — when you select a butterfly valve, you should take into full account the influence of pressure loss in the pipeline system, and should fully consider the medium pressure the disc can bear in the pipeline when the valve is closed. In addition, the working temperature the elastic valve seat material can take under high temperature should also be considered.

3. The butterfly valve has smaller structural length and overall height, can be open or closed quickly, and is characterized by its good fluid control. The structure principle of butterfly valve shows that these kind of valves are more suitable to be made into large diameter ones. When butterfly valves are required to be used for flow control, the most important thing is to correctly select their specifications and types so that they can work properly and effectively.