Claims
- 1. A pipe connector, comprising:
a pin having external threads; a box having internal threads that mate with the pin external threads; the pin having a nose located at an extreme end of the pin; the box having a seal surface that engages the pin nose to form an internal seal; a rigid seal/support ring fixedly mounted on the exterior of the pin farther from the nose of the pin than the threads; and a mating seal surface in the box for engaging the rigid seal/support ring to provide bending support and form an external seal.
- 2. The connector according to claim 1, wherein the rigid seal/support ring is of a different material than the material of the pin.
- 3. The connector according to claim 1, wherein the rigid seal/support ring has a lower modulus of elasticity than the pin.
- 4. The connector according to claim 1, wherein the rigid seal/support ring has a conical exterior, and the mating seal surface in the box is conical.
- 5. The connector according to claim 1, wherein the rigid seal/support ring is mounted on the pin by a shrink- or press-fit.
- 6. The connector according to claim 1, wherein each of the internal and external threads comprises:
load flanks and stabbing flanks joined alternately by crests and roots; the load flanks being formed at a lesser angle than the stabbing flanks relative to a plane perpendicular to an axis of the connector; and the junction of each root with each load flank being formed by a portion of an ellipse that has a major axis that is at a smaller angle relative to the axis of the connector than a minor axis of the ellipse.
- 7. The connector according to claim 1, wherein the outer diameter of the box over the seal surface that mates with the rigid seal/support ring is less than the maximum outer diameter of the box.
- 8. A pipe connector, comprising:
a pin having a nose and external threads extending in a first direction from the nose; a metallic seal/support ring rigidly mounted on an exterior portion of the pin, the external threads being located between the metallic seal/support ring and the nose, the metallic seal/support ring having a tapered exterior seal surface; a box having a rim and internal threads that mate with the external pin threads; a first seal surface in the box for engaging the seal surface of the metallic seal/support ring to form an external seal; and a second seal surface located farther from the rim than the first seal surface in the box for engaging the pin nose to form an internal seal.
- 9. The connector according to claim 8, wherein the metallic seal/support ring has a lesser modulus of elasticity than the pin.
- 10. The connector according to claim 8, further comprising:
a step formed on the pin adjacent to the metallic seal/support ring opposite the threads, the step having an outer diameter larger than an inner diameter of the metallic seal/support ring to resist movement of the metallic seal/support ring in the first direction when the pin is screwed into the box.
- 11. The connector according to claim 8, further comprising:
a micro-knurled or roughened surface on the pin underlying the metallic seal/support ring to resist movement of the metallic seal/support ring.
- 12. The connector according to claim 8, further comprising:
an adhesive inserted between the pin and the metallic seal/support ring to resist movement of the metallic seal/support ring.
- 13. The connector according to claim 8, further comprising:
a shot-peened region of the pin underlying the metallic seal/support ring to resist movement of the metallic seal/support ring and enhance the fatigue performance of the connection.
- 14. The connector according to claim 8, comprising a coupling, the coupling having a box formed in each end for coupling two pins.
- 15. The connector according to claim 8, wherein the metallic seal/support ring is mounted on the pin by a shrink- or press-fit.
- 16. The connector according to claim 8, wherein the outer diameter of the box over the seal surface that mates with the metallic seal/support ring is less than the maximum outer diameter of the box.
- 17. The connector according to claim 8, wherein each of the internal and external threads comprises:
load flanks and stabbing flanks joined alternately by crests and roots; the load flanks being formed at a lesser angle than the stabbing flanks relative to a plane perpendicular to an axis of the connector; and the junction of each root with each load flank being formed by a portion of an ellipse that has a major axis that is at a smaller angle relative to the axis of the connector than a minor axis of the ellipse.
- 18. A pipe connector, comprising:
a nose formed on a forward end of a pipe, the nose having an external seal surface for sealing against a seal surface within a box; external threads formed on the pipe and extending rearward from the nose at a conical taper; and a metallic seal/support ring shrink-fit mounted on an exterior portion of the pipe rearward of the external threads, the metallic seal/support ring being of a lesser modulus of elasticity the pipe, the metallic seal/support ring having a tapered exterior seal surface for sealing against another seal surface within the box.
- 19. The pipe connector according to claim 18, further comprising:
a step formed on the pipe rearward of the metallic seal/support ring, the step having an outer diameter larger than an inner diameter of the metallic seal/support ring to resist rearward movement of the metallic seal/support ring.
- 20. A pipe connector, comprising:
a nose formed on a forward end of a pipe, the nose having an external seal surface for sealing against a seal surface within a box; external threads formed on the pipe and extending rearward from the nose at a conical taper; and a metallic seal/support ring press-fit mounted on an exterior portion of the pipe rearward of the external threads, the metallic seal/support ring being of a lesser modulus of elasticity the pipe, the metallic seal/support ring having a tapered exterior seal surface for sealing against another seal surface within the box.
- 21. The pipe connector according to claim 20, further comprising:
a step formed on the pipe rearward of the metallic seal/support ring, the step having an outer diameter larger than an inner diameter of the metallic seal/support ring to resist rearward movement of the metallic seal/support ring.
- 22. A method for manufacturing a pipe connector pin, comprising:
machining a nose on a forward end of a pin; machining an external seal surface on the nose; machining a set of external threads on the pin rearward from the nose; providing a metallic seal/support ring with an inner diameter slightly smaller than an outer diameter of the pin; heating the metallic seal/support ring to cause its inner diameter to enlarge and installing the metallic seal/support ring while still hot over the pin to a selected position, then cooling the metallic seal/support ring to cause its inner diameter to shrink and create an interference fit with the pin; and machining a tapered exterior seal surface on the metallic seal/support ring.
- 23. The method according to claim 22, wherein the step of machining the tapered exterior seal surface occurs after the metallic seal/support ring has been interference fit with the pin.
- 24. The method according to claim 22, further comprising forming a step on the pin rearward of the threads, and abutting the metallic seal/support ring against the step while inserting the metallic seal/support ring over the pin.
- 25. The method according to claim 22, further comprising forming a reduced outer diameter section on the pin rearward of the threads, defining a step, and positioning the metallic seal/support ring in the reduced outer diameter section and abutting the metallic seal/support ring against the step while inserting the metallic seal/support ring over the pin.
- 26. A tapered thread form for a pipe connector, comprising:
a load flank formed at first angle relative to a plane perpendicular to an axis of the connector; a stabbing flank formed at a second and greater angle relative to a plane perpendicular to an axis of the connector; a crest joining the load and stabbing flanks; a root joining the load and stabbing flanks opposite the crest; and the junction of the root with the load flank being formed by a portion of an ellipse that has a major axis that is at a smaller angle relative to the axis of the connector than a minor axis of the ellipse.
- 27. The thread form according to claim 26, wherein the major axis of the ellipse is substantially normal to the load flank.
- 28. The thread form according to claim 26, wherein the root has a contour that follows the ellipse from the junction of the root with the load flank substantially to a point where the root begins to transition to the stabbing flank.
Parent Case Info
[0001] This application claims the provisional application S. No. 60/314,766, filed Aug. 24, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60314766 |
Aug 2001 |
US |