The triple-offset butterfly valve is a kind of butterfly valve with outstanding performance in the industrial pipeline. According to the sealed form, the triple-offset butterfly valve belongs to the category of hard-sealing butterfly valve. Therefore, the triple-offset butterfly valve has the characteristics of a hard-sealed butterfly valve, high temperature resistance, erosion resistance, and a long service life. Because the three-eccentric butterfly valve directly welds the high-temperature corrosion-resistant alloy material to the valve seat surface, the valve also has the same excellent sealing performance as the soft sealing butterfly valve. What is the principle of triple eccentric butterfly valve? What are the three eccentricities of three eccentricities? Why use three eccentric structures?
Triple eccentric butterfly valve principle
The sealing surface of the triple-eccentric butterfly valve is a tapered conical surface. The valve seat of the valve body is in surface contact with the butterfly plate sealing ring. Its working principle is to drive the movement of the butterfly plate by operating the transmission device. During the movement of the butterfly plate, the sealing is performed. The ring is fully in contact with the valve seat because of the elastic deformation to achieve the seal.
The three-eccentric butterfly valve has a prominent feature is to change the sealing structure of the valve, no longer the traditional position seal, but the torque seal, that is, does not rely on the elastic deformation of the valve seat to achieve the seal, but rely on the butterfly plate sealing surface The contact surface pressure with the valve seat achieves the sealing effect, which also solves the problem of large leakage of the metal valve seat. Because the contact surface pressure is directly proportional to the medium pressure, the three-offset butterfly valve is stronger. High pressure and high temperature performance.
Three eccentric of triple eccentric butterfly valve
The first eccentricity: the deviation from the plane of the sealing surface to the valve stem centerline;
The second eccentricity: the distance from the centerline of the valve body to the centerline of the valve stem;
The third eccentricity: the centerline of the taper surface where the valve sealing surface is located and the centerline of the valve body passageway have an included angle.
Triple eccentric structure reason
The use of a triple eccentric structure can reduce the friction during switching between the sealing surface of the butterfly plate and the sealing surface of the valve body, so that the butterfly plate can quickly disengage or release the valve seat when the triple eccentric butterfly valve is opened or closed, thereby reducing the operation. Torque, more effort and lighter operation, increased the service life of the butterfly valve sealing surface.