Flat gaskets for internal combustion engines are described. The flat gaskets may be used in internal combustion engines, in particular in engines with liners.

A metal seal can be crushed evenly without forming wrinkles and scratches due to sliding against first and second flat surfaces. The seal comprises a first/second end surface arranged to face the first/second flat surface, respectively. The first end surface comprises a first convex part having a curved or flat surface that contacts the first flat surface, and a first projection that is formed shifted in a radial direction from the first convex part and has a ridge line that contacts the first flat surface. Prior to deformation, when the second end surface contacts the second flat surface and the first flat surface is separated from the first end surface, a point where a vertical distance between the first convex part and the second flat surface is the greatest and the ridge line are located on the same surface that is parallel to the first flat surface.

A metal seal is annular, provided sandwiched between first and second flat surfaces. The seal includes a first/second end surface opposite to the first/second flat surface, respectively. The first end surface includes paired first protrusions formed displaced in a radial direction of the metal seal and have dihedral angles contacting the first flat surface, and the second end surface includes a second protrusion formed inward of one first protrusion and outward of the other first protrusion in the radial direction, and has a dihedral angle contacting the second flat surface, and paired third protrusions that are respectively formed inward and outward of the second protrusion and whose highest points to which perpendicular distances from a reference plane including the dihedral angles of the paired first protrusions are shorter than a perpendicular distance from the reference plane to the dihedral angle of the second protrusion.

A method of sizing a cavity in a part and a part made from such method. The method includes forming the part having the cavity, including forming a plurality of protrusions extending within the cavity from at least one internal surface of the cavity, the protrusions having distal ends bordering an unobstructed portion of the cavity, the unobstructed portion having an initial dimension at least partially defined by a position of the distal ends, pressing a deforming element against the distal ends of the protrusions to plastically deform the protrusions toward the at least one internal surface of the cavity and increase the initial dimension to a final dimension, and disengaging the deforming element from the distal ends.

A heat exchanger includes a shell. A tubesheet is mounted to the shell. A plurality of tubes extend from the tubesheet and into the shell for heat exchange between a first fluid within the tubes and a second fluid in the shell outside the tubes. The tubesheet divides an interior of the shell into a heat exchange chamber where the tubes can exchange heat with the second fluid, an inlet-outlet chamber for the first fluid to enter and exit the tubes. A breech lock locks the tubesheet within the shell. A bi-directionally self-energizing gasket is seated between the tubesheet and the shell to seal the heat exchange chamber from the inlet-outlet chamber. The gasket is configured to be self-energizing to seal regardless of whether there is a higher pressure in the heat exchange chamber or in the inlet-outlet chamber.

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.

Provided is a metal gasket, which is used for connecting pipes to each other in a thermal power plant, a nuclear power plant, a steam engine in a steam turbine ship, an oil refinery line, a petrochemical industry process line, a semiconductor manufacturing line or the like, and which is characterized in that a V-shaped circumferential groove 2 is provided on the outer circumferential surface of the metal gasket 1, the ratio (circumferential groove depth A/horizontal length B) of the depth A of the circumferential groove 2 and the horizontal length B in a cross section of the metal gasket 1 is 0.1 to 0.95, and the notch angle of the V-shaped circumferential groove 2 is 30 to 120.

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 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.