Valve stem and valve disc connection for a diaphragm valve

Abstract

A valve body has a valve seat in the lower portion of a valve chamber with inlet and outlet openings communicating with the chamber for the flow of fluid therethrough. A valve assembly has a valve disc arranged to move into and out of abutting relation with the valve seat and a disc cap connected to the upper portion of the valve disc. A valve stem supported for axial, reciprocal movement within the valve chamber has a threaded upper portion connected to a rotatable bushing and a threaded lower portion connected to the disc cap. A flexible metal diaphragm assembly separates the valve chamber into the upper and lower portions and includes an axial bore through which the lower portion of the valve stem extends. A diaphragm stem clamp threadedly engaged to the valve stem lower portion securely abuts the top surface of the diaphragm. The disc cap is threadedly engaged to the lower portion of the valve stem on the opposite side of the diaphragm assembly and securely abuts the bottom surface thereof to provide a fluid tight seal between the diaphragm assembly and the valve stem where the valve stem extends through the diaphragm assembly. Downward and upward movement of the valve stem moves the valve disc into and out of abutting relation with the valve seat to assure positive opening and closing of the valve.