A top cap for a valve includes an upper surface; and a lower surface distal from the upper surface; wherein the upper surface and the lower surface of the top cap define a bore and a bore axis, the bore extending from the upper surface to the lower surface, the top cap defining: a minor bore of the bore, the minor bore intersecting the upper surface and defining a minor bore diameter; and a major bore of the bore, the major bore intersecting the lower surface and defining a major bore diameter, the major bore diameter greater than the minor bore diameter, the top cap including a bore shoulder, the bore shoulder defining a bore shoulder surface extending from the minor bore to the major bore, the bore shoulder surface angled with respect to the bore axis of the top cap.

A seat ring for a butterfly valve is mounted on an inner peripheral surface of an internal flow passage extending along the flow passage axis in a valve body of the butterfly valve, so that an outer peripheral edge surface of a valve element supported to be rotatable in the internal flow passage by a valve stem supported by the valve body abuts on the seat ring. The seat ring includes a ring body having a cylindrical shape and extending in the center axis direction, and the ring body is formed at positions opposite to each other in a radial direction of the ring body with a pair of through-holes for allowing the valve stem to pass through. On an outer peripheral surface of the ring body, arcuate projections extending in a circumferential direction are formed apart from the pair of through-holes.

The present invention relates to a fluoroplastic butterfly valve structure, including a valve body, a butterfly disc, a lining, and a back-up ring. The butterfly disc has a disc-like structure and includes an inner metallic butterfly disc and an outer fluoroplastic material enclosing the metallic butterfly disc. The butterfly disc is provided with a valve shaft and includes two bulging portions for connecting with the valve shaft. The butterfly disc has a board-like or cone-like cross section. The valve shaft is mounted in a shaft hole portion of the valve body, enabling rotation of the butterfly disc for adjusting flow amount or opening/closing the valve. The back-up ring and the fluoroplastic lining are mounted on an inner peripheral surface of the valve body. An outer rim of the butterfly disc and an inner surface of the lining are tightly pressed against each other by interference fit. The back-up ring is provided between the inner peripheral surface of the valve body and the lining and is made of high temperature resistance rubber in order for bearing the pressing pressure of deformation resulted from said interference fit, thereby meeting the requirement of working with a high-temperature (200 degree Celsius) and high-pressure fluid. The butterfly disc has a complex sealing structure, which includes an unequal-width conical surface and an unequal-width curved surface. The unequal-width curved surface is disposed in a closing direction of the butterfly disc for preventing interference sliding thereof with respect to the inner surface of the lining, thereby reducing deformation of lining and reducing torque. The unequal-width curved surface is composed of arc curves. A portion of the unequal-width curved surface which is at a position near the valve shaft has a longer arc, while a portion of the unequal-width conical surface which is at a position near the valve shaft has a smaller width, said smaller width exceeding 50 percent of a thickness of the outer rim of the inner metallic butterfly disc. Take a 3-inch butterfly disc as an example, where a thickness of the butterfly disc is 8 mm, a sealing width of the butterfly disc is greater than 4 mm. A portion of the unequal-width curved surface which is at a largest-diameter region of a central of the butterfly disc has a shortest arc, while a portion of the unequal-width conical surface which is at the largest-diameter region of the central of the butterfly disc has a largest width, said largest width exceeding 70 percent of the thickness of an outer rim of the inner metallic butterfly disc of the butterfly disc.

A butterfly valve which may enhance corrosion resistance or acid resistance with keeping its strength, have light weight and realize mass production, and method of manufacturing the same. are disclosed. The butterfly valve comprises a body in which an inserting space is formed and a disk inserted into the inserting space of the body, wherein fluid flow is opened or closed in response to rotation of the disk. Here, the disk includes a disk body formed of a metal, and at least one plastic layer formed on the disk body.

A valve device includes a shaft, a valve body, and a housing including a valve opening. An outwardly facing surface of the valve body is out of contact with the housing and a valve-facing surface is in contact with the housing in a fully closed state in which the valve body closes the valve opening. A valve seal surface includes a first valve seal surface protruding in a valve closing direction and a second valve seal surface recessed in a valve opening direction. A first seal distance in a radial direction from an outer diameter end of the first valve seal surface to a rotation axis is shorter than a second seal distance in the radial direction from an outer diameter end of the second valve seal surface to the rotation axis. The first valve seal surface and the second valve seal surface each have at least a curved surface.

A valve and coupling for joining pipe elements has a valve body captured in a central space defined by a plurality of coupling segments attached to one another end to end. The inner surface of the valve body defines a bore. A liner on the inner surface surrounds the bore and forms a seal with a valve closing member. Circumferentially arranged projections on the segments engage and center the valve body within the central space. The liner has lobes that extend axially in opposite directions. The lobes are compressed between the segments and the pipe elements to form a fluid tight seal when connection members are tightened to draw the segments toward the central space and into engagement with the pipe elements.

A valve and coupling for joining pipe elements has a valve body captured in a central space defined by a plurality of coupling segments attached to one another end to end. The inner surface of the valve body defines a bore. A liner on the inner surface surrounds the bore and forms a seal with a valve closing member. Circumferentially arranged projections on the segments engage and center the valve body within the central space. The liner has lobes that extend axially in opposite directions. The lobes are compressed between the segments and the pipe elements to form a fluid tight seal when connection members are tightened to draw the segments toward the central space and into engagement with the pipe elements.

A valve includes: a valve body defining a shaft bore therethrough, an axis of the shaft bore defining a vertical axis; a valve shaft positioned within and configured to rotate within the valve body; a valve disc coupled to the valve shaft and positioned within the valve body, the valve disc configured to rotate within the valve body between an open position and a closed position; and a valve seat positioned within the valve body, the valve seat including an outer surface in contact with the valve body and an inner surface in contact with the valve disc, the inner surface of the valve seat defining a sealing ridge extending radially inward with respect to the vertical axis, the sealing ridge having an annular shape about the valve shaft, the sealing ridge concentric with the valve shaft.

A seat ring for a butterfly valve is mounted on an inner peripheral surface of an internal flow passage extending along the flow passage axis in a valve body of the butterfly valve, so that an outer peripheral edge surface of a valve element supported to be rotatable in the internal flow passage by a valve stem supported by the valve body abuts on the seat ring. The seat ring includes a ring body having a cylindrical shape and extending in the center axis direction, and the ring body is formed at positions opposite to each other in a radial direction of the ring body with a pair of through-holes for allowing the valve stem to pass through. On an outer peripheral surface of the ring body, arcuate projections extending in a circumferential direction are formed apart from the pair of through-holes.

A top cap for a valve includes an upper surface; and a lower surface distal from the upper surface; wherein the upper surface and the lower surface of the top cap define a bore and a bore axis, the bore extending from the upper surface to the lower surface, the top cap defining: a minor bore of the bore, the minor bore intersecting the upper surface and defining a minor bore diameter; and a major bore of the bore, the major bore intersecting the lower surface and defining a major bore diameter, the major bore diameter greater than the minor bore diameter, the top cap including a bore shoulder, the bore shoulder defining a bore shoulder surface extending from the minor bore to the major bore, the bore shoulder surface angled with respect to the bore axis of the top cap.