Metallic seal
A metallic seal is provided that concentrates the available load over a narrow band to produce a sealing dam over a sufficient width to minimize leakage on a molecular level. The metallic seal has a first annular beam section, a second annular beam section, and inner and outer surfaces extending between the first and second annular beam sections. One of the inner and outer surfaces has an annular recess that at least partially defines an annular column section of material extending substantially perpendicular between said first and second annular beam sections thereto. The first annular beam section has a first non-sealing surface and a first raised portion with a first annular sealing surface facing in a first axial direction to contact a first member for creating a first annular sealing dam therebetween. The second annular beam section has a second non-sealing surface and a first raised portion with a second annular sealing surface facing in a second axial direction, which is opposite to the first axial direction, to contact a second member for creating a second annular sealing dam therebetween. The annular inner surface extends between the first and second sealing surfaces to form a central passageway. The metallic seal is used to create a seal between a pair of mating surfaces of a first member and a second member. First and second members are coupled together by a plurality of fasteners or bolts. By tightening the fasteners the seal is loaded, and thus, compressed to plastically deform and create an annular seal between the first and second members.
1. A metallic seal comprising:
a first annular beam section having a first non-sealing surface and a first raised portion, said first raised portion having a first annular sealing surface facing in a first axial direction to contact a first member for creating a first annular sealing dam therebetween;
a second annular beam section having a second non-sealing surface and a second raised portion, said second raised portion having a second annular sealing surface facing in a second axial direction, which is opposite to said first axial direction, to contact a second member for creating a second annular sealing dam therebetween;
an annular inner surface extending between said first and second sealing surfaces to form a central passageway;
an annular outer surface extending between said first and second sealing surfaces and spaced from said annular inner surface to form an annular column section of material extending substantially perpendicular between said first and second annular beam sections thereto; and
one of said annular inner and outer surfaces having an annular recess extending in a substantially radial direction to at least partly define an effective minimum width of said annular column section,
at least a part of said first sealing surface of said first raised portion and at least a part of second sealing surface of said second raised portion being axially aligned with said annular column section, said first and second non-sealing surfaces being axially aligned with said annular recess and extending radially from said one of said annular inner and outer surfaces having said annular recess.
2. The metallic seal according to claim 1 , wherein
said annular recess is configured to form a first diagonal brace section extending from said annular column section to said first beam section.
3. The metallic seal according to claim 2 , wherein
said column section and said beam sections are integrally constructed from a one-piece, unitary member.
4. The metallic seal according to claim 2 , wherein
said effective minimum width of said column section lies within the range of approximately 0.008 inch to approximately 0.030 inch.
5. The metallic seal according to claim 2 , wherein
a second diagonal brace section extends from said annular column section to said second beam section.
6. The metallic seal according to claim 5 , wherein
said first and second brace sections meet approximately midway between said annular sealing surfaces at said annular column section.
7. The metallic seal according to claim 6 , wherein
each of said first and second brace sections extends from said column section at an angle of approximately 35° to approximately 55°.
8. The metallic seal according to claim 1 , wherein
said first and second sealing surfaces are located axially over only said annular column section.
9. The metallic seal according to claim 1 , wherein
said first and second sealing surfaces are located at one of said annular inner and outer surfaces.
10. The metallic seal according to claim 1 , wherein
said first and second sealing surfaces are substantially flat to form flat sealing lines upon compression.
11. The metallic seal according to claim 10 , wherein
said flat sealing surfaces are substantially parallel to each other.
12. The metallic seal according to claim 11 , wherein
said flat sealing surfaces are substantially perpendicular to a center axis of said metallic seal.
13. The metallic seal according to claim 1 , wherein
said column section has its axial height between said sealing surfaces at least as high as said effective minimum width.
14. The metallic seal according to claim 13 , wherein
said height of said column section is at least three times as long as minimum width of said column section.
15. The metallic seal according to claim 1 , wherein
said first brace section extends from said column section at an angle of approximately 35° to approximately 55°.
16. The metallic seal according to claim 1 , wherein
said annular column section has an axial height lying between approximately 0.020 inch to approximately 1.0 inch.
17. The metallic seal according to claim 1 , wherein
said annular recess is located approximately midway between said annular sealing surfaces.
18. The metallic seal according to claim 1 , wherein
said annular recess is located closer to one of said first and second annular sealing surfaces.
19. The metallic seal according to claim 1 , wherein
said annular recess is formed in said annular inner surface.
20. The metallic seal according to claim 1 , wherein
said annular recess is formed in said annular outer surface.
21. The metallic seal according to claim 1 , wherein
said seal is formed of a corrosion resistant alloy.
22. The metallic seal according to claim 1 , wherein
said seal is formed of a material selected from the group of pure nickel, copper, tin, aluminum and stainless steel.
23. A metallic seal comprising:
a first annular beam section having a first non - sealing surface and a first raised portion, said first raised portion having a first annular sealing surface facing in a first axial direction to contact a first member for creating a first annular sealing dam therebetween;
a second annular beam section having a second non - sealing surface and a second raised portion, said second raised portion having a second annular sealing surface facing in a second axial direction, which is opposite to said first axial direction, to contact a second member for creating a second annular sealing dam therebetween;
an annular inner surface extending between said first and second sealing surfaces to form a central passageway;
an annular outer surface extending between said first and second sealing surfaces and spaced from said annular inner surface to form an annular column section of material extending substantially perpendicular between said first and second annular beam sections thereto; and
one of said annular inner and outer surfaces having an area of reduced strength extending in a substantially radial direction to at least partly define an effective minimum width of said annular column section,
at least a part of said first sealing surface of said first raised portion and at least a part of said second sealing surface of said second raised portion being axially aligned with said annular column section, said first and second non - sealing surfaces being axially aligned with said area of reduced strength and extending radially from said one of said annular inner and outer surfaces having said area of reduced strength.
24. The metallic seal according to claim 23 , wherein
said area of reduced strength is formed by a recess.
25. The metallic seal according to claim 24 , wherein
said recess is continuous around said one of said annular inner and outer surfaces.
26. The metallic seal according to claim 25 , wherein
said recess has a constant cross - sectional profile.