A sealing structure includes an O-ring and a back-up ring. An outer diameter of the back-up ring is smaller than an inner diameter of a mounting portion of a delivery pipe. An inner diameter of the back-up ring is gradually increased from a pressure-receiving surface toward a seating surface, and is greater than an outer diameter of a fuel introducing portion of a fuel injection valve. In a section of the back-up ring, an edge angle defined between the pressure-receiving surface and an inner circumferential surface is smaller than a gap angle defined between the pressure-receiving surface and a tapered outer surface of a tapered portion in the fuel introducing portion. A dimension of the seating surface in the back-up ring is shorter than a dimension in an end surface.

A blowout preventer (BOP) and a seal anti-extrusion apparatus is provided for well control about a tubular such as a polish rod. Each of opposing ram blocks support a semi-circular primary seal and at least one downstream backup ring. An extrusion gap is formed between the ram block and the rod. The backup ring has profile that is axially compressible by the primary seal when activated, causing an inner diameter diminish, and closing the extrusion gap for improved sealing integrity of the primary seal.

The present invention provides fire-resistant seal assemblies that are particularly suited for use in hydraulic components in fire zones. The fire-resistant seal assemblies include a first seal made from an elastomeric material; a first anti-extrusion seal having a first seal-facing surface for receiving the first seal and defining a groove extending therealong, and an exterior surface having a truncated V-shaped portion with beveled end portions in a longitudinal cross sectional view; at least one second anti-extrusion seal having a second seal-facing surface for receiving the first anti-extrusion seal and defining a groove extending therealong, and an exterior surface having a truncated V-shaped portion with beveled end portions in a longitudinal cross sectional view; and at least one backer ring having a third seal-facing surface for receiving the second anti-extrusion seal and defining a groove extending therealong, and an exterior surface having a truncated V-shaped configuration in a longitudinal cross sectional view.

A seal structure of a high-pressure tank including: the first member in which a tank chamber is formed inside; and the second member which is fitted into the opening hole of the first member and provided with an annular groove formed on an outer peripheral surface, the seal structure includes: a seal member, having an annular shape, configured to be disposed on the tank chamber side in the groove; and a first back-up member and a second back-up member configured to be disposed further to the side opposite to the tank chamber side than the seal member in the groove, to include inclined surface parts respectively opposite to each other. The inclined surface part of the first back-up member includes a crest folding corner part in which a first low angle inclined part and a first high angle inclined part are connected to each other.

A fugitive emissions packing set is provided. The packing set a top ring and a bottom ring made from a fluoropolymer that includes a filler that enhances the mechanical and/or dimensional stability of the ring, as compared to unfilled fluoropolymer. The intermediate rings are formed from an essentially pure fluoropolymer. The top, bottom, or intermediate rings may include a metal insert in any combination.

A seal assembly includes: a first seal element; and a pressing element. The first seal element is a groove ring and has a first seal lip and a second seal lip. The pressing element is arranged between the first seal lip and the second seal lip and effects a radial pre-tensioning of the first seal lip and the second seal lip. The pressing element closes a gap between the first seal lip and the second seal lip.

[Problem] To provide a sealing device having high pressure-resistance and durability for a reciprocating shaft.

[Solution] A sealing device comprising an oil seal member and a dust seal member. The oil seal member and the dust seal member each comprise a rigid ring provided inside a shaft hole and an elastic ring attached to the rigid ring, wherein the elastic ring has formed thereon a lip for slidably contacting a reciprocating shaft. The sealing device further comprises an intermediate rigid ring provided between the elastic ring of the oil seal member and the elastic ring of the dust seal member, in a direction parallel to the axial direction of the reciprocating shaft.

Supported face seal assemblies and related methods are disclosed. The supported face seal assemblies have spring energized seal element supported by a backing ring. When the two components are joined, they form an interlocking face seal assembly that is less prone to separate during installation and/or service. The methods disclosed include the steps of forming a spring energized sealing element with a convex outer surface, forming a backup or support ring with a concave inner surface, assembling the sealing element into the inner bore of the backup or support ring such that the concave inner surface accepts a portion of the convex outer surface and the sealing element is retained within the backup or support ring.

The annular dust seal includes a circular annular dust lip, the annular dust seal being formed of an elastic material, being supported by a housing, and bringing a surface of the dust lip into contact with an outer peripheral surface of a reciprocating shaft that is disposed in the housing and includes a tip end side protruding toward an atmosphere side. In a longitudinal section of the dust lip, an average radius of curvature of a surface having a convex curvature on an inner side of the housing from a top portion of the dust lip is larger than an average radius of curvature of a surface having a convex curvature on the atmosphere side from the top portion of the dust lip.

A composite circular connector seal, or an assembly comprising a plurality of such seals, may be engineered to seal across a predetermined tolerance band for such seals by using two substantially circular seal elements sized to slidingly fit about a tubular that has a positive and negative outer diameter tolerance range, where each seal element is terminated at one circumferential edge with a packer cap, and a core element disposed intermediate the two substantially circular seal elements at their respective non-packer cap terminated circumferential edges. The two substantially circular seal elements comprise an organic thermoplastic polymer and the core seal element, which typically comprises a synthetic rubber, is also typically molded to the two seal elements at their respective non-packer cap terminated circumferential edges.