Boss seal for composite overwrapped pressure vessel
A pressure vessel is disclosed. The pressure vessel may include a boss, a liner, an O-ring, and a composite overwrap of shell. A boss may comprise a through aperture, a first groove encircling the through aperture, and a first engagement mechanism. A liner may comprise an interior surface, exterior surface, and a second engagement mechanism. The interior surface may define an interior cavity of the pressure vessel. The second engagement mechanism may mechanically engage the first engagement mechanism to secure the liner to the boss. An O-ring may be positioned within the first groove of the boss and abut the exterior surface of the liner. A composite overwrap may surround the liner and at least a portion of the boss.
1. A method of manufacturing a pressure vessel, the method comprising:
positioning a boss as an insert within a mold, the boss comprising a through aperture, a first groove encircling the through aperture, an engagement mechanism, and an O-ring positioned within the first groove;
molding, within the mold after the positioning, a polymeric container such that a portion of the polymeric container is molded directly against the O-ring;
the molding comprising engaging, by polymeric material of the polymeric container, the engagement mechanism to secure the polymeric container to the boss; and
removing, after the molding, the boss and polymeric container as a unit from the mold.
2. The method of claim 1 , further comprising wrapping, after the removing, the polymeric container and at least a portion of the boss with a composite material.
3. The method of claim 1 , wherein:
the O-ring has a convex surface; and
the molding further comprises forming the polymeric material to abut and substantially match the convex surface of the O-ring.
4. The method of claim 1 , wherein:
the engagement mechanism comprises a first undercut cavity formed in the boss; and
the molding further comprises filling the first undercut cavity with the polymeric material.
5. The method of claim 4 , wherein:
the engagement mechanism further comprises a second undercut cavity formed in the boss; and
the molding further comprises filling the second undercut cavity with the polymeric material.
6. The method of claim 5 , wherein the first undercut cavity comprises a second groove encircling the through aperture.
7. The method of claim 6 , wherein the second undercut cavity comprises a third groove encircling the through aperture.
8. The method of claim 7 , wherein the first, second, and third grooves are concentric.
9. The method of claim 8 , wherein the second groove is interior to the first groove.
10. The method of claim 9 , wherein the first groove is interior to the third groove.
11. A method of manufacturing a pressure vessel, the method comprising:
positioning a boss as an insert within a mold, the boss comprising a through aperture, a first groove encircling the through aperture, an engagement mechanism, and an O-ring positioned within the first groove;
molding, within the mold after the positioning, a liner to have an interior surface and an exterior surface, the interior surface defining an interior cavity of the pressure vessel;
the molding comprising molding the exterior surface directly against the O-ring;
the molding further comprising engaging, by material of the liner, the engagement mechanism to secure the liner to the boss; and
wrapping, after the molding, the liner and at least a portion of the boss with a composite material.
12. The method of claim 11 , wherein:
the boss comprises a flange extending radially away from the through aperture, the flange having a first side facing a first direction and a second side facing a second direction substantially opposite to the first direction; and
the first groove is formed in the first side of the boss.
13. The method of claim 12 , wherein
the engagement mechanism comprises a first undercut cavity formed in the first side of the boss; and
the molding further comprises filling the first undercut cavity with the polymeric material.
14. The method of claim 13 , wherein:
the engagement mechanism further comprises a second undercut cavity formed in the first side of the boss; and
the molding further comprises filling the second undercut cavity with the polymeric material.
15. The method of claim 14 , wherein the first undercut cavity comprises a second groove encircling the through aperture.
16. The method of claim 15 , wherein the second undercut cavity comprises a third groove encircling the through aperture.
17. The method of claim 16 , wherein the first, second, and third grooves are concentric.
18. The method of claim 17 , wherein the second groove is interior to the first groove.
19. The method of claim 18 , wherein the first groove is interior to the third groove.
20. A method of manufacturing, the method comprising:
positioning an insert within a mold, the insert comprising a metal component, a groove formed in the metal component, an engagement mechanism, and a seal component positioned within the first groove;
molding, within the mold after the positioning, a polymeric component such that a portion of the polymeric component is molded directly against the sealing component;
the molding comprising engaging, by polymeric material of the polymeric component, the engagement mechanism to secure the polymeric container to the boss;
removing, after the molding, the metal component and the polymeric component as a unit from the mold; and
sealing, by the sealing component, an interface between the metal component and the polymeric component.