Importance

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Abstract

A metal seal for valves, especially disk valves, for use in pipelines through which fluid media flow. The seal ring has at least one, relatively flexible metal or metal composite seal ring which can be mounted to either the housing or the disk of the valve. The seal ring has a flat attachment section from which a curved, in cross-section generally U-shaped, sealing lip extends which, in the closed position of the valve, engages a metallic seating surface of the latter. The seal ring is attached to the valve without separate mounting elements, such as screws or bolts, by welding a free, radial end of the seal ring to a relatively rigid support ring secured to either the housing or the disk of the valve by shrinking engagement. The shrink engagement is a frictional engagement between the support ring and the valve attained by providing the seal ring with a cylindrical shrink surface which has a diameter slightly larger than the diameter of a cooperating cylindrical mounting surface of the valve when the two have the same temperature. Just prior to the installation of the seal ring, its temperature is lowered sufficiently so that the outer diameter of the shrink surface becomes less than the inner diameter of the mounting surface of the valve. In this condition the seal ring is axially inserted into the valve and, thereafter, its temperature is permitted to rise to that of the valve. This increases the diameter of the engagement surface. Expansion is restrained by the surrounding cylindrical mounting surface of the valve. As a result, frictional forces are generated between them which retain the seal ring in its operative position.

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First Claim