What is the sealing principle of the three eccentric butterfly valve?

The sealing principle of the three eccentric butterfly valve is based on its unique three eccentric structure design, which forms an elliptical sealing surface through the combination of three eccentricities, achieving torque sealing of the metal hard sealed butterfly valve and fundamentally solving the friction damage and leakage problems of traditional butterfly valves.

Specifically, the sealing principle of the three eccentric butterfly valve includes the following core points:

Triple eccentric structure: The axis of the valve stem of the triple eccentric butterfly valve deviates from both the center of the butterfly plate and the center of the body, and the rotation axis of the valve seat forms an angular sealing structure with the axis of the valve body channel. This design ensures that there is almost no friction between the valve plate and the valve seat during the opening and closing process of the butterfly valve, greatly improving the service life and sealing performance of the valve.

Torque sealing mechanism: The sealing of the three eccentric butterfly valve is no longer position sealing, but torque sealing. When the butterfly valve is closed, the sealing pressure between the two sealing surfaces of its sealing pair is generated by the driving torque applied to the valve stem. This sealing mechanism effectively compensates for the tolerance zone between the shaft sleeve and the valve body, as well as the elastic deformation of the valve stem under medium pressure, solving the sealing problem that exists in the bi-directional exchange of medium transportation in valves.

Non frictional contact of sealing surface: The sealing surface of the three eccentric butterfly valve is a slanted cone structure, and the shape of the valve plate sealing surface is therefore asymmetric from top to bottom. When the butterfly valve is opened from 0 ° to 90 °, the sealing surface of the valve plate will detach from the sealing surface of the valve seat at the moment of opening; When it is closed from 90 ° to 0 °, only at the moment of closure, the sealing surface of the valve plate will contact and press the sealing surface of the valve seat. This design ensures no friction between the valve seat and the sealing surface on the butterfly plate, eliminating the possibility of wear and leakage.

Adjustable sealing performance: The sealing pressure ratio of the three eccentric butterfly valve can be adjusted arbitrarily by changing the external driving torque, thereby improving the sealing performance of the three eccentric butterfly valve and greatly increasing its service life.