Abstract: Disclosed is a plug and seal assembly comprising an annular seat ring and a plug head for use in a fluid control valve utilized for regulating a flow of high-pressure fluid. The seat ring includes first, second, and third sealing discs alternately stacked with respective first, second and third resilient bearing discs. The inner annular edges of the first, second and third sealing and bearing discs collectively define a conical sealing surface. The plug head defines stepped first, second and third ramps, each ramp having a truncated conical shape of equal half-angle with the conical sealing surface half-angle being larger than the ramp half-angle. The direct engagement of the first, second and third ramps against respective ones of the sealing discs acts to deform the respective ones of the bearing discs to create three fluid-tight seals therebetween to reduce the risk of leakage of the valve when in a closed position.

Abstract: A valve stem sealed by a packing. A spigot applies an axial compression loading to the packing via a sleeve when bolts are tightened. A clamp attaches two parts of the valve body to each other with the bolts extending between the spigot and the clamp. The bolt and spigot provide an integral spring construction.

Abstract: A valve (100) has a valve stem (150) sealed by packing (160). A gland spigot (180) applies an axial compression loading to the packing (160) via a sleeve (130) when bolts (240, 250) are tightened. The spigot (18) has arms (190, 200) with slots (400, 401) that divide the arms (190, 200) into upper and lower branches (402, 403). The branches (402, 403) arc urged towards each other on tightening the bolts (240, 250) to pre-load the packing and act as integral springs to maintain the compression loading in use of the valve (100). The deflection of the branches (402, 403) is limited by one or more washers (251, 252) located on the bolts (240, 250) between the branches (402, 403) to control the loading applied to the packing (160).