Triple eccentric butterfly valve

Abstract

The object of this invention is to relieve a jet from a clearance part in microscopic opening; and to eliminate a vacuum area in an orifice side valve element back face, by improving a flow rate characteristic in the microscopic opening, in a triple eccentric butterfly valve. In this triple eccentric butterfly valve, first of all, the center of a valve stem is made primarily eccentric by separating from the center of a valve seat surface formed on an outer peripheral surface of a valve element and a valve seat surface of a valve body; next, the center of the valve stem is secondarily made eccentric by separating from the center of the valve body; and is made in the three-dimensional arrangement eccentric by inclining to the center line of the valve body while positioning the apex of a conical shape for constituting the valve seal surface on the opposite side of the valve stem. An obverse surface and a reverse surface of the valve element are mutually formed in parallel, and both the obverse and reverse surfaces are set to an inclined surplus power angle to a central plane of a seating surface of the valve body and the valve element. The central plane is vertically positioned to the axis of a fluid passage when fully closing a valve. Opening clearance of the valve is started from the nozzle side of the valve element when opening the valve. The clearance is continuously expanded to the orifice side in response to rotation.

Description

technical field [0001] The invention relates to a triple eccentric butterfly valve which is installed on pipelines dealing with various fluids, especially high-temperature and high-pressure fluids, and is used for opening and closing or controlling flow paths. Background technique [0002] Conventionally, triple eccentric valves are known that open and close or control a flow path through which a high-temperature, high-pressure fluid flows. The butterfly valve is a valve body in which a substantially cylindrical fluid passage is penetrated, and a disc-shaped valve body is freely rotatably supported so that the rotation shaft (valve stem) of the valve body extends out of the valve body and is connected with the transmission. The device is connected to drive the rotation. Among the butterfly valves, especially when dealing with high-temperature and high-pressure fluids, triple eccentric butterfly valves with special structures are reused. The triple eccentric butterfly valve...

AI Technical Summary

Problems solved by technology

However, this butterfly valve also does not take into account the relaxation of the jet stream from the gap portion or the elimination of the vacuum area on the back side of the valve body on the side of the orifice when the opening is small.

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