Patent EA-004342-B1 (EA)
Title: Threaded tubular element
Inventor: VERDILLON LIONEL
IPC: F16L15/00
Filed: 2001-03-26
Abstract: 1. A threaded tubular element, male or female (2, 51, 62) having an anti anti-fatigue profile for threaded tubular joint (100, 200) and resistible against external mechanical effect both statically and cyclically changing realized at the end of the pipe (101, 102, 202), containing a male thread on the external peripheral surface or female thread (4) on the internal peripheral surface such as said threaded element is male or female, wherein said threaded tubular element comprises a cut in form of groove (30, 31) of the wall of threaded element (3, 4) on the peripheral surface (103, 104) of the threaded tubular element opposite to that surface, where the thread is made without affecting the geometries of threads (11, 12) of the threading, characterized in that the wall under the threading is reduced by means of annular groove (30, 31)at least on the level of the first threads to be engaged in such way to decrease the stiffness. 2. Threaded tubular element, according to claim 1, characterized in that the annular groove begins under the first thread to be engaged (21, 22). 3. Threaded tubular element, according to claim 1 or 2, characterized in that the annular groove ends on the axial interval between first section of the threading and the threading, located on the level of the last threads to be engaged. 4. Threaded tubular element, according to any of claims 1-3, characterized in that the annular groove (30, 31) possesses the form of figure of revolution relatively to the axis (XX) of the threaded tubular element. 5. Threaded tubular element, according to any of claims 1-4, characterized in that the annular groove (30, 31) decreases under it the stiffness of the wall, comprising threads, made in variable and progressive manner along the axial direction of threaded tubular element. 6. Threaded tubular element, according to claim 5, characterized in that on the level of annular groove a thickness of the wall under the threading is minimal in transversal plane (40, 41), located in the interval between the first engaged thread (21, 22) and sixth engaged thread (28, 29). 7. Threaded tubular element, according to claim 6, characterized in that on the level of annular groove the minimal wall thickness under the threading (emin1, emin2) exceeds and is equal to the height of the thread profile (hf) 8. Threaded tubular element, according to claim 6, characterized in that the minimal wall thickness under the threading (emin1, emin2) is substantially equal to two times the height of the thread. 9. Threaded tubular element, according to claim 6, characterized in that the wall thickness under the threading is minimal and constant on the axial distance different of zero. 10. Threaded tubular element, according to any of claims 6-9, characterized in that because of annular groove, the wall thickness under the threading has the value in the range from 100% to 120% of the minimal wall thickness under the threading in the zone (EF' HI), or in so called zone of small stiffness, located around the transversal plane of minimal wall thickness under the threading (40, 41), said zone of small stiffness passing at the axial length, exceeding or equal to three thread pitches. 11. Threaded tubular element, according to any of claims 1-10, characterized in that the annular groove profile is such, that critical section of the threaded element for the traction efforts is placed out of the zone of removing of material in the groove. 12. Threaded tubular element, according to any of claims 1-11, characterized in that because of annular groove, the wall thickness under the threading on the level of three last engaged threads has the value in the range from 80% to 100% from the thickness out of the zone of removing of material in the groove. 13. Threaded tubular element, according to any of claims 1-12, characterized in that the annular groove contains lateral surfaces (36,37,38,39), the angle of inclination of which in relation to the axis of said threaded tubular element has the value, smaller or equal to 45 degree . 14. Threaded tubular element, according to claim 13, characterized in that the lateral surface of the annular groove, located by the side of the free end of threaded element (36,37), has mainly steeper slope in relation to the axis of that threaded element, than the lateral surface of that annular groove (38, 39), located by the opposite side of threaded element. 15. Threaded tubular element, according to any of claims 1-14, characterized in that the profile of the annular groove represents a regular curve formed by the series of arcs of circles, having finite or infinite radiuses, connected tangentially with each other. 16. Threaded tubular element, according to any of claims 1-15, characterized in that the annular groove is connected with the common part of peripheral surface, not containing the zone of material removing, in said part the annular groove is being made, by means of tangential zone of connection (32, 33, 35), having the toroidal form. 17. Threaded tubular element, according to any of claims 1-16, characterized in that the annular groove is partially or entirely filled with material (50), the module of elasticity being of it being lesser than the module of elasticity of material, of which the threaded tubular element is prepared. 18. Threaded tubular element, according to any of claims 1-17, characterized in that the threading is the threading with the trapezoidal threads. 19. Threaded tubular connection (100, 200) destined to resist against the external mechanical effects of both static and cyclically changing character, comprising male threaded tubular element, located in the end of first tube (101) connected by means of screwing with female threaded tubular element, located on the end of the second tube (102, 202), by means of male threading (3), made on the male threaded tubular element, and female threading (4), made on the female threaded tubular element, characterized in that at least one of threaded tubular elements, male or female, represents threaded tubular element of type of element (2, 51, 62) according to any claims 1-18. 20. Threaded tubular connection (100, 200) according to claim 19, characterized in that both threaded tubular elements, male and female, represent the threaded tubular elements of type of elements (2, 51, 62) according to any of claims 1-18.