Single eccentric butterfly valve: In order to solve the compression problem between the butterfly plate and the valve seat of the concentric butterfly valve, a single eccentric butterfly valve has emerged. Its structural feature is that the valve stem axis deviates from the center of the butterfly plate, so that the upper and lower ends of the butterfly plate no longer become the rotation axis, dispersing and reducing the excessive compression between the upper and lower ends of the butterfly plate and the valve seat. Double eccentric butterfly valve: Based on the single eccentric butterfly valve, the widely used double eccentric butterfly valve is further improved and formed. Its structural feature is that the valve stem axis deviates from both the center of the butterfly plate and the center of the body. The double eccentricity effect allows the butterfly plate to quickly detach from the valve seat after the valve is opened, greatly eliminating unnecessary excessive compression and scraping between the butterfly plate and the valve seat, reducing the opening resistance distance, reducing wear, and improving the service life of the valve seat. Triple eccentric butterfly valve: must be resistant to high temperatures, must use hard seals, but has a large leakage rate; To achieve zero leakage, a soft seal must be used, but it is not resistant to high temperatures. To overcome the contradiction of the double eccentric butterfly valve, a third eccentricity was carried out on the butterfly valve. The so-called third eccentricity refers to the shape of the sealing pair not being a regular cone, but an oblique cone. Eccentric butterfly valve is opposite to concentric butterfly valve. A butterfly valve with a valve stem axis that deviates from both the center of the disc and the center of the body, and a sealing pair with an inclined cone, is called an eccentric butterfly valve.

Structural classification of eccentric butterfly valves

Single eccentricity

In order to solve the squeezing problem between the butterfly plate and the valve seat of the concentric butterfly valve, a single eccentric butterfly valve was produced. Its structural feature is that the valve stem axis deviates from the center of the butterfly plate, so that the upper and lower ends of the butterfly plate no longer become the rotating axis, dispersing and reducing the excessive squeezing between the upper and lower ends of the butterfly plate and the valve seat.

Double Eccentricity

The widely used double eccentric butterfly valve is further improved and formed on the basis of single eccentricity. Its structural feature is that the valve stem axis deviates from both the center of the butterfly plate and the center of the body. The double eccentricity effect allows the butterfly plate to quickly detach from the valve seat after the valve is opened, greatly eliminating unnecessary excessive compression and scraping between the butterfly plate and the valve seat, reducing the opening resistance distance, reducing wear, and improving the service life of the valve seat.