Ultra-seal gasket for joining high purity fluid pathways
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.
1. A ring-shaped gasket for sealingly joining opposed fluid conduit ports, the gasket comprising:
a gasket body comprising a radial outer surface, a first axial end surface, and a second axial end surface, the gasket body comprising a through hole creating a fluid pathway and defining a radial inner surface;
wherein the first axial end surface comprises a first stress concentration feature formed in the gasket body to define a first lip on the first axial end surface, the first lip comprising a first sealing surface, the first stress concentration feature comprising a first surface adjacent the first axial end surface,
wherein the second axial end surface comprises a second stress concentration feature formed in the gasket body to define a second lip on the second axial end surface, the second lip comprising a second sealing surface, the second stress concentration feature comprising a second surface adjacent the second axial end surface,
a first plurality of stress concentration cavities, each comprising a first blind cavity projecting into the first surface, a first cavity opening proximate the first lip, the first lip being configured to plastically deform in response to the first sealing surface contacting a first face surface of a first fluid conduit port, and
a second plurality of stress concentration cavities, each comprising a second blind cavity projecting into the second surface, a second cavity opening proximate the second lip, the second lip being configured to plastically deform in response to the second sealing surface contacting a second face surface of a second fluid conduit port
wherein the first plurality of stress concentration cavities are interleaved with the second plurality of stress concentration cavities.
2. The gasket of claim 1 , wherein a first outer periphery of the first plurality of the stress concentration cavities is surrounded by a portion of the first axial end surface that extends axially outward to a lesser extent than the first lip prior to installation of the gasket and wherein a second outer periphery of the second plurality of the stress concentration cavities is surrounded by a portion of the second axial end surface that extends axially outward to a lesser extent than the second lip prior to installation of the gasket.
3. The gasket of claim 1 , wherein each of the first plurality of stress concentration cavities comprises an asymmetrical cylindrical shape with a curved bottom, where the first cavity opening is formed in the first axial end surface and wherein each of the second plurality of stress concentration cavities comprises an asymmetrical cylindrical shape with a curved bottom, where the second cavity opening is formed in the second axial end surface.
4. The gasket of claim 3 , wherein the gasket comprises a malleable material.
5. The gasket of claim 4 , wherein the gasket comprises one of a unitary metallic material substantially identical to stainless steel alloys and a unitary metallic material selected from the group consisting of a stainless steel alloy, a chromium alloy, a nickel alloy, commercially pure nickel, a copper alloy, and commercially pure copper.
6. The gasket of claim 3 , wherein an axial extent of the gasket body adjacent the radial inner surface of the gasket is less than an axial extent of the gasket body adjacent the radial outer surface.
7. The gasket of claim 3 , wherein the second sealing surface further comprises a circumferential sector exhibiting a generally constant angle with respect to the second axial end surface.
8. The gasket of claim 1 , wherein the first lip further comprises a first protective ridge adjacent the first sealing surface.
9. The gasket of claim 8 , wherein the first protective ridge is disposed radially outward of the first sealing surface.
10. The gasket of claim 1 , wherein the second lip further comprises a second protective ridge adjacent the second sealing surface.
11. The gasket of claim 10 , wherein the second protective ridge is disposed radially outward of the second sealing surface.
12. The gasket of claim 1 , wherein the first protective ridge is disposed radially outward of the sealing surface.
13. The gasket of claim 1 , wherein each of the first plurality of stress concentration cavities is configured to form an undercut of the first sealing surface.
14. The gasket of claim 13 , wherein each of the second plurality of stress concentration cavities is configured to form an undercut of the second sealing surface.
15. The gasket of claim 1 , wherein the interleaving of the first plurality of stress concentration cavities and the second plurality of stress concentration cavities comprises the first plurality of stress concentration cavities being anti-phase interposed with the second plurality of stress concentration cavities.
16. The gasket of claim 1 , wherein the first sealing surface further comprises a circumferential sector exhibiting a generally constant angle with respect to the first axial end surface.
17. The gasket of claim 1 , wherein the first plurality of stress concentration cavities further comprise the first cavity openings facing a first direction and the second plurality of stress concentration cavities further comprise the second cavity openings facing a second direction.
18. The gasket of claim 1 , wherein the first axial end surface and the second axial end surface are each configured to function as a hard stop to prevent excessive compression of the first lip and the second lip.