Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L15/00—Screw-threaded joints; Forms of screw-threads for such joints
  • F16L15/001—Screw-threaded joints; Forms of screw-threads for such joints with conical threads
  • F16L15/004—Screw-threaded joints; Forms of screw-threads for such joints with conical threads with axial sealings having at least one plastically deformable sealing surface
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
  • E21B17/042—Threaded

Definitions

• the invention relates to a pipe connection according to the preamble of claim 1
• Pipe connectors are used to connect tubular elements, such as
• a contact surface for example, which is cylindrical in the socket element in a thread-free section, interacts with a contact surface, for example, convexly formed of the pin element.
• Such a connection frequently has a butt shoulder of the socket and pin element serves as
• Screw-in limitation should ensure by appropriate pre-tensioning that the adjacent metallic sealing seat remains activated despite increasing tensile load.
• the elastic expansions occurring under load or compression of the socket and pin element lead to the contact area with the highest surface pressure at the apex of the metallic
• the sealing seat can be axially displaced and the surface pressure can be reduced so that the tightness is no longer guaranteed for the highest internal or external pressure permitted for the pipe.
• the object of the invention is to provide a pipe connection which, taking into account the manufacturing tolerances, ensures that an adequate sealing effect of the metallic sealing seat remains guaranteed under all loading conditions.
• the contact zone having a shorter distance from the end of the lip is designed as a protective seat and the contact zone having a further distance from the end of the lip is designed as a sealing seat.
• the term lip is used here as a synonym for the thread-free section of the pin element.
• a distance to the thread inlet and a degree of deflection is selected for the sealing seat, which produces a surface pressure in the sealing seat of at least six times the theoretically required surface pressure, but at most 90% of the yield strength in relation to the material used, the degree of deflection becoming ever greater is as the thread overlap in the area of the thread inlet.
• deflection chosen here should be understood to mean the following: Due to the geometrical oversize (overlaps) in the contact zones and in the thread area, primarily at the thread inlet, as well as through the introduction of forces through a butt shoulder, a bent line is generated in the screwed state in the socket and pin element, which has locally different radial displacements in the form of deflections.
• the objective is to generate radial, tangential and if possible also axially negative stresses and thus to minimize the reference stress (von Mises).
• High harmful tensile bending stresses as a result of an unfavorable bending moment curve are avoided by the optimized positioning of the contact zone as well as by the controlled superimposition of transverse forces and bending moments introduced elsewhere.
• These overlapping transverse forces and bending moments are generated by the protective seat, which is positioned at a significantly smaller distance from the end of the lip compared to the sealing seat.
• the protective seat also has the task of stabilizing the sealing seat by shielding it against external forces.
• the protective seat has a larger deflection depending on the degree of deflection of the sealing seat in the range of 1.15 to 1.30 times, based on the sealing seat.
• Figure 7 in longitudinal section a system of protective and sealing seat of a shock-free
• the lip 4 unthreaded portion of the pin element in the upper part - as the more critical part, compared to the sleeve element, as a thin-walled, short hollow cylinder with less
• the left side of the diagram shows an example of the positioning of a contact zone on the lip 4. If circumferential forces F u are now introduced in this plane, they generate a deflection 1 (solid line), transverse forces 2 (dashed line) and bending moments 3 (dotted line), which decay in the form of strongly damped vibrations The frequency of these vibrations and thus the longitudinal extension of the loads and geometric changes are determined by the geometry of the lip 4 (radius, thickness)
• the magnitude of the loads and deformations depends on the magnitude of the circumferential force and at what distance from the end 5 of the lip 4 it engages.
• forces are up to four times greater depending on the distance High required In the right part of the figure, this case is indicated by the higher circumferential force Fu 'by the longer arrow F u ' compared to F u.
• the transverse forces 2' and bending moments 3 ' are also significantly higher, where the bending moments 3 'in the contact zone are of opposite sign compared to those on
• the circumferential forces are generated by a predetermined deflection (overlap in the contact zone) when screwing in. Depending on the positioning of the
• the sub-images a - c show the deflection 1 2 for a lip with two contact zones (seats) with an optimal distance selection of the seat 1 (protective seat) and the seat 2 (sealing seat) from the lip end or from the butt end on the one hand and from the thread inlet on the other - 1 2 ", the transverse forces 2 2 - 2 2" and the bending moments 3 2 - 3 2 "plotted
• the solid line represents the optimum if, according to the invention, the forces acting in the seat 1 (protective seat) influence the load on the seat 2 (sealing seat).
• sub-picture a it can be seen that the Deflection
• seat 1 in seat 1 is chosen to be larger than in seat 2, namely according to the invention in a range of 1, 15 to 1, 30 times.
• the overlapping of forces and moments in the two seats 1, 2 according to the invention is particularly the sub-images b and c
• the arrangement of a protective seat (seat 1) reduces the lateral forces
• Figure 3 shows the influence of a biasing force with the radial component 6 when arranging a shoulder with a small abutment angle.
• the division into the partial images a - c is the same as in Figure 2.
• the applied radial component 6 is removed in the partial image b at the lip end, namely as a positive transverse force It can be seen that the transverse force 2 3 in the seat 2 (sealing seat) is practically not influenced.
• the bending moment 3 3 in the partial picture c which is considered to be harmful, has in fact become somewhat lower due to the pretensioning in comparison with FIG.
• FIG. 4 shows the influence of the angle of the butt shoulder on deflection (a)
• Shear force (b) and bending moment (c) shown in partial image b it can be clearly seen that when the impact angle is greater than 10 degrees (15 ° in the example) the shear forces 2 4 "are reduced compared to 2 4 in the sealing seat while they are in the seat 1 more than doubled, which leads to comparative stresses that exceed the yield point. It is therefore preferable that the angle is less than 10 degrees (in the example 6 °), which has no influence in the sealing seat (2 4 'compared to 2 4). The change in the state of tension in the protective seat also remains within permissible limits.
• the protective function of the seat 1 can be clearly seen from the illustrations b and c, that even with a small butt angle at the lip end, forces have an effect up to the thread inlet, but do not have any harmful influence in the sealing seat itself
• FIG. 5 shows the distances between the lip end and protective seat, protective seat and sealing seat, sealing seat and thread inlet, which are optimized according to the invention, and the resulting deflections, shear forces and bending moments (lines 1 5, 2 5, 3 5)
• FIG. 6 shows a sleeve and a pin element in a design according to the invention.
• the sleeve element 7 has an internal threaded section 8, which extends from the end face 9 to the unthreaded section 10.
• the area 10 is closed by a butt shoulder 11
• In the unthreaded section 10 are in Contact area 12 of the sealing system according to the invention arranged two spherically contoured seats 13, 14 of which the seat 13 closer to the shoulder 11 is designed as a protective seat and the seat 14 further away is designed as a sealing seat.
• the radii of the balls are marked with corresponding arrows weak negative bevel 15 of ⁇ 10 degrees between the thread end 16 and the contact surface area 12 there remains a transition section 17 for extending the thread cutting tool.
• the pin element 18 has an external one
• Threaded section 19 which is complementary to the threaded section 8 of the sleeve element 7.
• the outer threaded section 19 then runs out into the initial thickness 20 of the tube 21 or the thread inlet 22, a thread-free section 23 is located, which then merges into a butt shoulder 24, which with the Butt shoulder 11 of the sleeve element 7 cooperates From the shoulder 24, a conical jacket surface 25 extends beyond the position of the spherical seats 13, 14 of the sleeve element 7.
• the remaining jacket surface 26 of the unthreaded section 23 can be continued with the same cone or to increase the elasticity of the lip with a lower inclination or cylindrical
• FIG. 7 shows a section of the embodiment of a bumpless pipe connection according to the invention.
• the conical jacket surface 25 of the pin element 18 is replaced by a double-conical contour.
• the pin element 30 points to the rest of the jacket surface
• the seat 34 which is further away from the end surface 36 of the pin element 30 forms the sealing seat and the nearby seat 35 forms the protective seat, this being provided with a more strongly inclined conical surface 33 the protective seat 38 provided with a convex spherical contour compared to
• a conical outer surface can be designed which corresponds to the cone 33 of the pin element 30

Landscapes

• Engineering & Computer Science (AREA)
• Geology (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Fluid Mechanics (AREA)
• Physics & Mathematics (AREA)
• Geochemistry & Mineralogy (AREA)
• Environmental & Geological Engineering (AREA)
• Gasket Seals (AREA)
• Non-Disconnectible Joints And Screw-Threaded Joints (AREA)
• Pressure Vessels And Lids Thereof (AREA)
• Joints With Pressure Members (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7877013

Family Applications (1)

Country Status (8)

Families Citing this family (6)

Family Cites Families (4)

• 1998
  • 1998-07-31 DE DE19836088A patent/DE19836088C1/de not_active Expired - Fee Related
• 1999
  • 1999-07-16 AU AU60781/99A patent/AU6078199A/en not_active Abandoned
  • 1999-07-16 WO PCT/DE1999/002222 patent/WO2000008367A2/de not_active Application Discontinuation
  • 1999-07-16 BR BR9912666-4A patent/BR9912666A/pt not_active IP Right Cessation
  • 1999-07-16 EP EP99947235A patent/EP1099071A2/de not_active Withdrawn
  • 1999-07-16 JP JP2000563967A patent/JP2002522713A/ja active Pending
  • 1999-07-29 AR ARP990103757A patent/AR023032A1/es unknown
• 2001
  • 2001-01-30 NO NO20010508A patent/NO20010508L/no not_active Application Discontinuation

Non-Patent Citations (1)

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