Threaded element of a component with opposed threading portions and corresponding tubular threaded connection

1. A threaded element of a component, comprising:

a free end and at least first and second threading portions each comprising threads each comprising a stabbing flank and a loading flank, said first threading portion being closest to said free end and said second threading portion being closest to a central non-threaded portion of said component,

wherein the stabbing flanks and the loading flanks of the threads of said first threading portion and the threads of said second threading portion are inclined in an opposed manner with respect to a radial direction, in a cross section along a longitudinal axis of the said element.

2. A threaded element according to claim 1 , wherein an angle of inclination with respect to the radial direction of the stabbing flanks of the threads of the first threading portion of a male threaded element or of the second threading portion of a female threaded element is negative.

3. A threaded element according to claim 1 , wherein an angle of inclination with respect to the radial direction of the loading flanks of the threads of the first threading portion of a male threaded element or of the second threading portion of a female threaded element is positive.

4. A threaded element according to claim 1 , wherein the absolute value of an angle of inclination with respect to the radial direction of the stabbing flanks of the threads of the first threading portion of a male threaded element or of the second threading portion of a female threaded element is lower than the absolute value of an angle of inclination with respect to the radial direction of the loading flanks of the threads of the first threading portion of a male threaded element or of the second threading portion of a female threaded element.

5. A threaded element according to claim 4 , wherein the absolute value of an angle of inclination of the stabbing flanks of the threads of the first threading portion of a male threaded element or the second threading portion of a female threaded element is in a range from about 3° to about 15°.

6. A threaded element according to claim 4 , wherein the absolute value of an angle of inclination of the loading flanks of the threads of the first threading portion of a male threaded element or of the second threading portion of a female threaded element is in a range from about 10° to about 30°.

7. A threaded element according to claim 1 , wherein the absolute value of an angle of inclination with respect to the radial direction of the stabbing flanks of the threads of said second threading portion of a male threaded element or of the first threading portion of a female threaded element is greater than the absolute value of an angle of inclination with respect to the radial direction of the loading flanks of the threads respectively of said second threading portion of a male threaded element or of the first threading portion of a female threaded element.

8. A threaded element according to claim 7 , wherein the absolute value of an angle of inclination of the loading flanks of the threads of said second threading portion of a male threaded element or of the first threading portion of a female threaded element is in a range from about 3° to about 15°.

9. A threaded element according to claim 7 , wherein the absolute value of an angle of inclination of the stabbing flanks of the threads of said second threading portion of a male threaded element or the first threading portion of a female threaded element is in a range from about 10° to about 30°.

10. A threaded element according to claim 4 , wherein the algebraic value of an angle of inclination of the stabbing flanks of the threads of said first threading portion is substantially equal to the algebraic value of an angle of inclination of the loading flanks of the threads of said second threading portion.

11. A threaded element according to claim 4 , wherein the algebraic value of an angle of inclination of the loading flanks of the threads of said first threading portion is substantially equal to the algebraic value of an angle of inclination of the stabbing flanks of the threads of said second threading portion.

12. A threaded element according to claim 1 , wherein said first and second threading portions are tapered.

13. A threaded element according to claim 12 , wherein said second threading portion is formed after a radial shoulder of a desired radial extension.

14. A threaded element according to claim 12 , wherein said first and second threading portions are disposed substantially on a same tapered surface.

15. A threaded element according to claim 1 , wherein said first and second threading portions are straight and formed at first and second radial distances from a longitudinal axis of said component.

16. A threaded element according to claim 1 , wherein said first and second threading portions are axially separated by an intermediate zone which extends over an axial distance selected so as to absorb external loads and/or to take up an axial clearance between the first or second threading portion of a threaded element and respectively the second or first threading portion of a matching threaded element, by essentially elastic deformation.

17. A threaded element according to claim 16 , wherein the axial extent of the intermediate zone is proportional to the maximum value of said axial clearance.

18. A threaded element according to claim 16 , wherein the minimum value of the axial clearance is an increasing function of thread height and the absolute value of negative angle of the flank.

19. A threaded element according to claim 16 , wherein at least a portion of said intermediate zone defines a sealing surface that can come into tight interference contact with a corresponding sealing surface of another threaded element.

20. A threaded tubular connection, comprising:

a threaded male type element and a threaded female type element in accordance with claim 11 , which match so that they can be made up one into the other.

21. A threaded tubular connection according to claim 20 , wherein said first and second threading portions are disposed so that, once made up and in absence of external tensile, compressive or bonding loads, the stabbing flanks of the threads of said first threading portion of the female threaded element are in contact with those of said second threading portion of the male threaded element corresponding thereto, and the loading flanks of the threads of the second threading portion of the female threaded element are in contact with those of the first threading portion of the male threaded element corresponding thereto, providing a first buffer zone between the loading flanks of threads which correspond in the first threading portion of the female threaded element and in the second threading portion of the male threaded element, and providing a second buffer zone between the stabbing flanks of threads which correspond in the second threading portion of the female threaded element and in the first threading portion of the male threaded element, said first buffer zones being intended to take up an axial clearance in presence of a tensile load and said second buffer zones being intended to take up an axial clearance in presence of a compressive load.

22. A threaded male or female element of a component, comprising:

a free end and at least first and second threading portions adapted to be made up onto two threading portions of a respectively female or male threaded element of another component to constitute a made up assembly with said other component, each comprising threads each comprising a stabbing flank and a loading flank, said first threading portion being closest to said free end and said second threading portion being closest to a central non-threaded portion of said component,

wherein the stabbing flanks and the loading flanks of the threads of said first threading portion and the threads of said second threading portion are inclined in an opposed manner with respect to a radial direction.