A steering shaft according to an aspect of the present invention includes an upper shaft, a lower shaft, and a seal cap. The seal cap includes a seal which comes into close contact with an inner peripheral surface of the upper shaft and a closure which bulges upward with respect to the seal. The closure is plastically deformed downward, and thus, the seal cap is held in an upper end opening portion in a state where the seal is pressed against the inner peripheral surface of the upper shaft.

A soluble metal sealing ring with a controllable dissolution rate and preparation process thereof include an aluminum alloy sealing ring matrix and a composite coating coated on an outer surface of the aluminum alloy sealing ring matrix whose standard electrode potential is greater than -0.3 volts (V). The preparation process includes: (1) preparing a high-plastic aluminum alloy; (2) preparing the aluminum alloy sealing ring matrix by machining; (3) annealing the aluminum alloy sealing ring matrix; (4) mixing raw materials of the composite coating evenly; (5) preparing the composite coating on an outer surface of the aluminum alloy sealing ring matrix; (6) preparing holes. The soluble metal sealing ring solves problem that good sealing performance and good dissolving performance are difficult to obtain simultaneously in the existing product, and has advantages of good sealing performance, controllable dissolving rate, no blockage and others.

A ring-shaped gasket for making high-purity fluid pathway connections between opposing fluid delivery apparatus elements having at least one simple flat surface in contact with the gasket. The face of at least one apparatus element typically has a circular counterbore depression to receive the gasket, but is not required. The gasket has a body, pierced through by a hole creating a fluid pathway and defining a radial inner surface, and additionally having a radial outer surface, a first axial end surface and a second axial end surface. At least one of the first and second axial end surfaces has a stress concentration feature radially adjacent to a gasket sealing region, the sealing region constructed to be in contact with a face surface of a corresponding fluid conduit port. The stress concentration feature may be a groove or a plurality of cavities disposed adjacent the gasket axial end surface sealing region.

Systems of the present disclosure relate to metal-to-metal seals for oilfield tubulars. A pin for a metal-to-metal seal, comprises a pin nose and a support structure. A gap extends between the pin nose and the support structure.

An annular seal system for sealing between a casing hanger and a wellhead housing, the system including an actuator ring having a rigid portion and a flexible portion, and a lockdown ring positioned adjacent the actuator ring. The annular seal system further includes a seal assembly capable of moving between a de-energized position and an energized position, wherein the seal assembly in the de-energized position has a defined a space between the seal assembly and the rigid portion of the actuator ring, wherein the seal assembly in the energized position has the space closed, wherein the rigid portion of the actuator ring is to contact a surface of the casing hanger, wherein the flexible portion of the actuator ring is to push the lockdown ring into engagement with the wellhead, and wherein the flexible portion of the actuator ring adapted is to axially compress to allow positional variation between the lockdown ring and the wellhead housing.

A static metal seal comprising an outer sealing layer, wherein the outer sealing layer comprises a textured surface that is configured to come into contact with the surfaces that are to be sealed, the textured surface comprising a network of depressions spaced apart from one another on the textured surface, wherein the depressions are blind, do not pass all the way through the outer sealing layer, and do not communicate with one another.

A metal sealing ring (1) for forming a metal-to-metal seal between two opposing metal surfaces. The metal sealing ring (1) comprises a tubular metal body (3) and an inlet tube (7) extending from the body (3) for introducing an internal pressure into the body (3). The body is adapted to deform under the internal pressure against each of the opposing metal surfaces to form the seal (1).

A ring-shaped gasket for making high-purity fluid pathway connections between opposing fluid delivery apparatus elements having at least one simple flat surface in contact with the gasket. The face of at least one apparatus element typically has a circular counterbore depression to receive the gasket, but is not required. The gasket has a body, pierced through by a hole creating a fluid pathway and defining a radial inner surface, and additionally having a radial outer surface, a first axial end surface and a second axial end surface. At least one of the first and second axial end surfaces has a stress concentration feature radially adjacent to a gasket sealing region, the sealing region constructed to be in contact with a face surface of a corresponding fluid conduit port. The stress concentration feature may be a groove or a plurality of cavities disposed adjacent the gasket axial end surface sealing region.

A low-spread metal ring gasket includes a lower ring gasket portion having a bottom surface and an upper ring gasket portion having an upper surface. The lower ring gasket portion includes at least one ring gasket sealing surface extending upward from the bottom surface, and the upper ring gasket portion includes at least one sealing bump protruding upward form the upper surface.

An extrusion resistant gasket may have a metallic core having a first side and a second side. The metallic core may have a plurality of alternating domes and valleys integrally formed therein. The domes and valleys do not have perforations through the core. The gasket may also have a non-metallic facing material on at least one of the sides of the metallic core. The facing material may have a contact surface and an inner surface. The domes or valleys do not extend through the contact surface.