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Which is better to use, triple eccentric butterfly valve or double eccentric butterfly valve

Posted by Bundor valve
Question: Hello! Butterfly valve has triple eccentric butterfly valve and double eccentric butterfly valve. Apart from the literal meaning, what are the main differences between the two kinds of butterfly valves? Triple eccentric butterfly valve and double eccentric butterfly valve which is better?
 
Bundor valve: The double eccentric butterfly valve is further improved on the basis of the single eccentric butterfly valve, which is also the most widely used. The structure is characterized in that the valve stem axis deviates from both the center of butterfly plate and the center of body.
 
The effect of double eccentric soft sealing butterfly valve enables the butterfly plate to quickly separate from the valve seat after the valve is opened, greatly eliminating the unnecessary over extrusion and scraping between the butterfly plate and the valve seat, reducing the opening distance, reducing the wear and improving the service life of the valve seat.
 
The double eccentric butterfly valve can also adopt the metal seat, which improves the application of the butterfly valve in the field of high temperature. However, the sealing principle is position sealing structure, that is, the sealing surface of butterfly plate and valve seat is in line contact, and the sealing effect is produced by the elastic deformation which caused by the butterfly plate pressing the valve seat. Therefore, the requirements for the closing position are very high (especially for the metal valve seat), and the pressure bearing capacity is low. This is why people traditionally think that the butterfly valve is not resistant to high pressure and has a large amount of leakage.
 
When the butterfly valve used in high temperature environment, must use hard seal, but the leakage is large; to zero leakage, must use soft seal, but cannot be used in high temperature environment. In order to overcome the contradiction of double eccentric butterfly valve, the triple eccentric of butterfly valve was carried out.
 
The structure of triple eccentric butterfly valve is, When the axis position of the double eccentric valve rod is eccentric,the conical axis of the sealing surface of the butterfly plate is inclined to the axis of the main cylinder. That is to say, after the third eccentric, the sealing section of butterfly plate is no longer a circle, but an ellipse, and the shape of the sealing surface is asymmetric, one side is inclined to the center line of the body, the other side is parallel to the body centerline.
 
Double eccentric butterfly valve is designed with eccentric structure, which is widely used in the fluid pipeline system of water supply and drainage, sewage, construction, petroleum, chemical industry, light textile, papermaking, hydropower, metallurgy, energy and other projects for regulation and closure.
 
Triple eccentric butterfly valve is used in oil exploitation, oil refining, petrochemical, energy power generation and other major industrial areas of important pipelines, and as people continue to research, I believe triple eccentric butterfly valve will be applied to more and more fields.
 
The application range of triple eccentric butterfly valve and double eccentric butterfly valve is different, so it can't compare which one is better ;
 
Bundor valve reminds you to select matching valves reasonably according to your actual working conditions. If you have any questions, please consult online customer service.