Bi-directional sealing elastic tri-eccentric butterfly valve

Abstract

The invention relates to a bi-directional sealing elastic tri-eccentric butterfly valve which has the characteristics that a packing seat, a packing component and a packing gland are successively installed to a packing box of the valve body and are fixed by locking nuts and screw rods, and then, the packing box is sealed; the packing component is pretightened by tightening the locking nuts on the screw rods, and a valve plate is fixedly connected with a valve rod through a straight pin; the axis of the valve rod is eccentric with the center of the valve plate and the center of the sealing surface of the valve plate, and the tapered axis of the sealing surface of the valve plate deflects from the cylindrical axis of the valve body; a thrust ring is installed between the valve body and the valve plate, vertical positioning is performed based on the upper and lower surfaces of the axis housing on the back surface of the valve plate as well as the stepped surfaces of the thrust ring, and the valve plate rotates around the valve rod to close or open the valve. The bi-directional sealing elastic tri-eccentric butterfly valve has the advantages that the sealing surface of the valve plate has uniform stress, and the friction and the torque are low, thereby reducing wear and effectively prolonging service life; sealing pressure ratio of a sealing ring to the valve plate can be increased to realize bi-directional sealing, and mediums cannot leak from the connection between the sealing ring and a pressing ring or the valve body.

Description

technical field [0001] The invention relates to a bidirectional sealing elastic sealing triple eccentric sealing butterfly valve, more specifically a butterfly valve capable of realizing bidirectional sealing and belonging to the field of fluid control valves. Background technique [0002] As is well known, the body of a butterfly valve is usually a cylindrical member that allows fluid to flow through it. It is characterized in that the valve plate rotates around the valve shaft as the center, close to or away from the sealing joint surface with the valve seat. Therefore, such a valve has two sealing surfaces, one sealing surface is on the valve seat in the valve body, and the other sealing surface is on the valve plate. When the disc rotates into contact with the seat, a seal is formed. [0003] Butterfly valves mainly include concentric butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves and triple eccentric butterfly valves. The struc...

AI Technical Summary

Problems solved by technology

However, because the principle of triple eccentricity belongs to the surface sealing structure, in the prior art, the sealing surface of the sealing ring on the valve plate and the valve seat on the valve body can only be single matched, and it is difficult to make batches of the sealing ring on the valve plate and the sealing surface on the valve body. The shape of the sealing surface of the valve seat is completely fitted and pressed

Since it is made in one piece, it cannot be replaced and repaired online

From the force analysis of the sealing ring, it can be seen that the overall sealing ring has the problem of uneven force and deformation around the sealing ring. Under the action of the valve stem torque, the sealing force and stress around the sealing ring are not etc., there are high pressure areas and bottom pressure areas, resulting in inconsistent deformation around the sealing ring

This inconsistent deformation along the periphery affects the sealing effect and service life of the valve

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