Abstract: A strengthened pipe fitting has an internally threaded surface and a compression band. The compression band is sized to compress the internally threaded surface sufficiently so that the pipe fitting is subjected to a compressive preload. The compression band is covered with a non-corrosive material.

Abstract: A flush-type integral threaded joint with truncated-cone threads, with two scaling surfaces 11?, 12?, 11?, 12?) set at the end of the threaded portions (7, 8), and with two annular scaling shoulders (5?, 6?, 5?, 6?). The two threaded portions (7, 8) of the male element (1) and female element (2), respectively, have the same value of conicity, and the two sealing surfaces (11?, 12?, 11?, 12?) are, in one case, conical or cylindrical, and in the other spherical. The threaded portion of each male and female element may have an end area with a thread that is not perfect.

Abstract: A threaded pin and box connection having thread geometries and/or dissimilar thread fits that prevent the pin thread of a connection from hanging up in the box thread as the pin is being stabbed into or destabbed from the box. Dissimilar geometries and/or threads include dissimilar thread types, dissimilar leads, overlapping leads, thread tooth widths of one component greater than thread grooves of the other component, multiple start threads, and combinations thereof.

Abstract: A connector arrangement used for connecting a first tubular to a second tubular. The first tubular member has at least one circumferential ring profile, and the second tubular member has a corresponding number of matching circumferential ring profiles. When the ring profiles of the two tubulars are mated and interlocked, they form separate and independent fluid seals as well as a mechanical lock able to hold the tubulars together during future expansion of the entire tubular and joint. Further, selecting properties of the tubulars such as yield strength and modulus of elasticity or constraining a diameter of one of the tubulars during expansion or compression forms a tight connection due to elastic recovery of the tubulars.

Abstract: An elongated drive string assembly includes a plurality of hollow sucker rods and connecting elements between a drive head located at the surface of an oil well and a rotary pump located deep down in an oil well, with a series of holes at each end to substantially increase the flow of extracted fluid. Each hollow sucker rod has a first end with a torque shoulder, which engages a torque shoulder formed on a connecting element. The threads are frusto-conical, non-symmetrical threads with a differential diametral taper. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string.

Abstract: A threaded attachment provides means of applying external threads to elongated members, such as tubes, rods, cables, and the like. The threaded attachment can be expanded to install around an elongated member. When the threaded attachment is compressed or closed around the elongated member, an adhesive liner on the inside surface of the threaded attachment bonds the threaded attachment concentrically to the elongated member.

Abstract: A threaded connection for a conduit is disclosed. The connection includes a male member having threads on it defining a load flank lead, a stab flank lead and a nominal lead. A female member has threads thereon adapted to mate with the threads on the male member. The threads on the female member define a load flank lead, a stab flank lead and a nominal lead. At least one of the load flank lead and the stab flank lead, on at least one of the female member and the male member, is changed at a predetermined rate beginning at a selected distance from an end of the threads. The load lead and the stab lead are different from each other over at least part of the thread length.

Abstract: A threaded metallic pipe for oil extraction industry has a threaded end portion with treated surface in which the metal surface has a roughness (Ra) comprised of 2.0 ?m and 6.0 ?m, which is covered by a uniform layer (7) of a dry corrosion inhibiting coating and a second uniform layer (8) of dry lubricant coating. Alternatively the layers (8, 9) combined into one uniform layer (9) of a dry corrosion inhibiting coating containing a dispersion of particles of solid lubricant.

Abstract: An expandable threaded connection between segments of expandable tubulars that provides multiple sealing points along the pin and box members that can withstand high pressure is disclosed. The present invention utilizes a gap that is created between the pin nose and the back of the box member when the threaded connection is made up and a reverse trapping angle machined into the pin nose end and the back of the box. The radial expansion of the tubulars causes axial movement of the pin nose and the box member until the pin nose is in contact with the back of the box member, thereby closing the gap and forcing the pin nose into sealing engagement with the back of the box member. The reverse trapping angle forces the nose of the pin member outwardly (i.e., toward the outer diameter of the expandable tubular string) as it is forced into contact with the back of the box member during the expansion process.

Abstract: A threaded joint which economically imparts effective sealing properties to a metal-to-metal seal portion and which can prevent seizing at the time of make-up comprises a steel pipe 1 having at its tip a male thread 1b and an unthreaded sealing surface 1a, and a coupling 2 having on its inner surface a female thread 2b and an unthreaded sealing surface 2a. With the yield pressure of the inner surface of the pipe being Py, (1) the average pressure Pm of the annular contact portion satisfies Pm/Py?3, and the width in the axial direction of the portion which receives a pressure Ps which satisfies Ps/Py?1 in the annular contact portion is at least 1 mm (or at least 2 mm), and the surface roughness Ry of both unthreaded sealing surfaces is at most 25 ?m (or at most 30 ?m), or (2) the relationship between the average pressure Pm of the annular contact portion and the surface roughness Ry (?m) of the unthreaded sealing surface satisfies Pm/Py?0.0032×Ry2+1.

Abstract: Described herein is a threaded joint, in which the threads are coated with a layer of dry lubricant having a thickness of between 5 ?m and 30 ?m and in which the nominal void volume NVV of the space (6, 7) between the thread of the male tube and the thread of the female tube, is sized by means of the following formulae: NVV ? [ cm 3 ] ? 4 × OD ? [ inch ] NVV ? [ cm 3 ] OD ? [ inch ] × Wt ? [ mm ] ? 1 g T ? 0.4 ? ? ? mm 2 ? / ? pitch where OD is the nominal outer diameter and Wt is the thickness of the wall of the pipes.

Abstract: Threaded pipe joint comprising a male element (1) and a female element (2), threaded and provided with respective complementary sealing surfaces, which define, when screwed together, a notch (13) formed on the female element (2) of a predetermined length (X), and a space (7, 8) between the threads of predetermined section (S), forming reservoir to house the joint lubricant, which comes out of the volume between the threads of the female (2) and male (1) elements during the tightening of the joint.

Abstract: A shoulder ring (10) for installing in the J-space between the installed pin ends within a coupling collar is taught having a body with a central opening therethrough, a first end face (12) on the body, an opposite end face (14) on the body, an inner surface (16) adjacent the central opening and extending between the first end face and the opposite end face and an outer surface (18) extending between the first end face and the opposite end face, the body having a substantially uniform cross sectional shape between the first end face, the opposite end face, the inner surface and the outer surface and the ring shaped such that its radius to the outer surface varies around the outer surface circumference to form a plurality of lobes (12).

Abstract: A toilet valve quick connect includes an upper housing having a capture chamber which facilitates the operation of a capture nut with oversized outward peripheral portions to enable it to be turned within the confines of a typical toilet tank. The toilet valve quick connect has a lower section which extends through the hole in a typical toilet tank and is secured in much the same way as a conventional toilet valve fitting. The toilet valve quick connect includes an internal conical sealing member for facilitating the sealed connection with the bottom rim and inside of a conventional toilet valve fitting. A capture housing partially encloses the capture nut to enable it to engage the threaded bottom fitting of a conventional toilet valve and to impress a downward force on the threaded bottom fitting.

Abstract: Threaded joint for pipes consisting of a male member (1) and a female member (2), which are provided on the outer and inner surfaces respectively with two threading portions presenting a lead-in flank ? such that 10°???25°, an abutment surface (9) being present at the end of said male member for abutment to a corresponding annular abutment surface (10) of the female member. The lead-in flanks of the male (1) and the female (2) members, upon make-up and with unloaded joint leave a gap (in the direction parallel to the axis (21) of the joint) varying from 0.01 to 0.12 mm. The internal and external diameters D3 and D4 (of the pipe portion not involved in the coupling with the female member) of said male member, the inner and outer diameters D1 and D2 of the abutment surface of the female member are linked by the relationship: (D22?D12)/(D42?D32)?0.5.

Abstract: A threaded pin and box pipe connection having makeup shoulders that contact when the pin and box threads are fully engaged. Upon initial engagement of the shoulders, load flanks of the pin and box threads furthest from the makeup shoulders engage each other and begin progressively separating from each other by an increasing amount along the length of the engaged threads in a direction from the end of the pin to a gauge point of the connection. Upon application of the makeup torque, the separation between the load flanks distributes the torque forces between the makeup shoulders along the length of the engaged threads to prevent concentration of stress forces near the base of the pin thread. The progressive separation of the load flanks is achieved by progressively changing the pitch of the load flank of the pin and/or box thread to vary the thread width. The separation of load flanks is achieved without modifications of the stab flank pitch.

Abstract: A hydraulic device having a nut part with a threaded hole which has an internal screw thread with a defined nominal diameter and with a defined, uniform pitch, and having a screw part which has an external screw thread with the same nominal diameter as the threaded hole and with a defined, uniform pitch, which is screwed into the threaded hole. (In hydraulic devices, screw parts, in particular nozzle bodies, are generally adhesively bonded in place, in order to prevent them from becoming detached. Adhesive bonding has certain drawbacks, since the screw threads have to be free of grease, and in the case of nozzles there is a risk of blockages, adhesive can enter the hydraulic circuit and also process reliability is not ensured during application.) There is provided a slight difference between the pitch of the internal screw thread of the nut part and the pitch of the external screw thread of the screw part.

Abstract: The premium threaded tubular connection comprises, on at least one threaded element, a distal abutment surface (7) at the free end of a threaded element and a lip sealing surface (5) at a given distance from the threading.

Abstract: A pipe fitting has a body with an internally threaded bore and at least one female starter thread. The at least one female starter thread is disposed either within the bore or immediately outside of the bore. The starter thread is axially aligned with the bore threads. The starter thread is made from a material which is stronger than the material from which the bore threads are made. The starter thread most proximate to the threads of the internally threaded bore has a pitch diameter which is at least two percent greater than the pitch diameter of the most proximate thread within the internally threaded bore.

Abstract: This invention relates to a threaded joint for steel pipes which comprises a pin and a box each having a contact surface including a threaded portion and an unthreaded metal contact portion and which can be prevented from galling during repeated fastening and loosening without application of a compound grease. A solid lubricant coating which comprises a lubricating powder such as molybdenum disulfide and a resin binder is formed on the contact surface of at least one of the pin and the box. The solid lubricant coating has a hardness of 70-140 on the Rockwell M scale and an adhesive strength of at least 500 N/m as determined by the SAICAS (Surface And Interfacial Cutting Analysis System) method, and it exhibits excellent galling resistance even in the environment of high-temperature oil wells. Inclusion of ultraviolet screening fine particles such as titanium oxide fine particles in the solid lubricant coating increases the rust preventing properties of the threaded joint.

Abstract: A quick-acting closure (1) for connecting a mixer tube (3) and a connecting part (2) of an extruder unit. The connecting part (2) has a connector (9) with a conical threaded base member, on which an external thread (12) is arranged. The mixer tube (3) has a conical threaded base member, on which an internal thread (19) is arranged. The internal thread (19) on the connector part (16) of the mixer tube (3) is a multi-path internal thread.

Abstract: A threaded joint for steel pipes comprising a pin 1 and a box 2 each having a contact surface comprising a threaded portion 3 or 4 and an unthreaded metal contact portion 8 is provided with improved anti-galling propertied by forming a lubricating coating on the contact surface of at least one of the pin and the box, the lubricating coating exhibiting a self-repairing function by liquid lubrication and having a decreased greasiness. The lubricating coating is (1) a coating which comprises a lower lubricant layer which is in liquid form in the temperature range of above 0° C. and below 40° C. and an upper lubricant layer which is in solid form at 40° C., or (2) a coating which is semi-solid or solid at 40° C. and is formed of a mixture comprising a lubricating oil which is in liquid form in the temperature range of above 0° C. and below 40° C. and a wax which is in solid form at 40° C.

Abstract: Oil country tubular goods and other types of tubular members are provided with threaded and coupled connections satisfactory for use in drilling and completing wellbores. The threaded and coupled connections are used to join sections of casing with each other to form a casing string which may be used to drill and complete a wellbore. Each tubular member has first and second pin ends with approximately the same thread form and thread profile with different pitch diameters. Standard API couplings may be used with the casing string.

Abstract: A threaded joint which economically imparts effective sealing properties to a metal-to-metal seal portion and which can prevent seizing at the time of make-up comprises a steel pipe 1 having at its tip a male thread 1b and an unthreaded sealing surface 1a, and a coupling 2 having on its inner surface a female thread 2b and an unthreaded sealing surface 2a. With the yield pressure of the inner surface of the pipe being Py, (1) the average pressure Pm of the annular contact portion satisfies Pm/Py≧3, and the width in the axial direction of the portion which receives a pressure Ps which satisfies Ps/Py≧1 in the annular contact portion is at least 1 mm (or at least 2 mm), and the surface roughness Ry of both unthreaded sealing surfaces is at most 25 &mgr;m (or at most 30 &mgr;m), or (2) the relationship between the average pressure Pm of the annular contact portion and the surface roughness Ry (&mgr;m) of the unthreaded sealing surface satisfies Pm/Py≧0.0032×Ry2+1.

Abstract: A fluid connector comprising a body having bore. Apertures disposed about a portion of the body allow a fluid flow to communicate with the bore. Sealing members on a body surface engage cooperating sealing surfaces on component members to be joined. An end of the body is formed to connect the fluid connector to a component member.

Abstract: A threaded tubular connection comprises two elements, male and female, made up one into the other to a given torque in which, prior to making up, at least one thread face under contact pressure (125) has a convexly rounded shape that is continuous over its width with a radius of curvature in the range 2 to 60 mm and is in point contact with the corresponding face (26) of the mating element. Such a threaded connection has an increased resistance to breakout or to overtorquing.

Abstract: Described herein is a threaded joint, in which the threads are coated with a layer of dry lubricant having a thickness of between 5 &mgr;m and 30 &mgr;m and in which the nominal void volume NVV of the space (6, 7) between the thread of the male tube and the thread of the female tube, is sized by means of the following formulae: 1 NVV ⁡ [ cm 3 ] ≤ 4 × OD ⁡ [ inch ] NVV ⁡ [ cm 3 ] OD ⁡ [ inch ] × Wt ⁡ [ mm ] ≤ 1 g T ≤ 0.

Abstract: A tubular assembly 10 is disclosed for passing fluids within a hydrocarbon recovery well. The tubular assembly 10 has an insulated connection 12 between insulated tubing segments 14, 16. Tubing segments 14, 16 are connected via a threaded connection, and the resulting joint 10 is insulated by an external insulating sleeve 18. The insulating sleeve 18 may have unitary construction, such that the sleeve 18 may only be installed or removed by first breaking apart the joint 10. Alternatively, the sleeve 18 may comprise a plurality of arcuate partial-sleeves, which may be assembled about or removed from the completed joint 10 without first breaking apart the joint 10.

Abstract: An externally threaded male hydraulic coupling member adapted for threaded and sealed attachment to a port body with a female port. The male coupling member having a tubular member with a threaded end, a bore extending through the member, a first cylindrical peripheral undercut portion longitudinally adjacent the threaded end, a series of intermediate external threads, and a second cylindrical undercut portion. The coupling member having a seal member and an annular ring member located in peripheral sealing contact with the first undercut portion. Wherein upon attachment, the seal member is encapsulated by the annular ring, the female port and the first undercut portion forming an annular chamber having a longitudinal extent greater than the seal member thickness. The coupling member also having a lock nut threadedly attached to the intermediate threads with a longitudinal end located between the annular ring and the intermediate threads.

Abstract: Fatigue-resistant threaded element for threaded tubular connection

Abstract: A pipe connection includes a threaded pin and a threaded box for securely forming a metal-to-metal seal. The pin includes an elongated thread section forming threads that are oriented with angled front and rear faces. The pin also includes a sealing surface for direct engagement with an interior surface of the box, preventing the exacerbation of corrosion of the threads.

Abstract: An elongated drive string assembly includes a plurality of hollow sucker rods and connecting elements with an axis, connected together and between a drive head located at the surface of an oil well and a rotary pump located deep down in an oil well. Each hollow sucker rod has at least a first end including an internal female threaded surface engaging an external male threaded surface on a connecting element, such as a nipple. The first end also includes a torque shoulder, which engages a torque shoulder formed on the connecting element. The threads are frusto-conical, non-symmetrical threads with a differential diametral taper. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string. The nipple has a wall cross-section that increases towards the torque shoulders from each free end, to increase fatigue resistance.

Abstract: There is disclosed a tubing connection arrangement and a method of coupling expandable tubing sections together. In one embodiment, there is disclosed a tubing connection arrangement (10) comprising a first expandable tubing section (12) defining a male portion (16); a second expandable tubing section (14) defining a female portion (18), the first and second expandable tubing sections (12, 14) being engageable with one another; one of the first and second expandable tubing sections (12, 14) including a restraining member (40) for restraining part of the other expandable tubing section (12, 14); and the first expandable tubing section (12) including a tapered shoulder (42,44) for co-operating with a corresponding tapered shoulder (46,48) of the second expandable tubing section (14).

Abstract: A submersible pump drop pipe and casing assembly and method of manufacture is disclosed. The drop pipe/casing has a seated connector and base. The seated connector has a first and second cylinder section, the first cylinder section being used to align and direct the base into the seated connector and to provide lateral strength to the pipe.

Abstract: Lubricant escape passages are formed in the threads used to connect one tubular body to another. The passages conduct trapped thread lubricant out of the threaded area to prevent the creation of high lubricant pressure that may damage or cause improper make up of the threaded connection. The passages may be grooves in the crests of the thread teeth and/or may be corner bevels on the thread teeth. In a conductor pipe or other pipe assembly using axially spaced internal and external seals at each axial end of the threaded area, the escape passages form a helical flow path through the engaged thread area. The external seal prevents the entry of corrosive fluids into the threaded area and the internal seal prevents leakage through the threaded area from within the conductor pipe. When the lubricant pressure increases excessively during assembly or impact loading of the connection, the lubricant escapes past the seals to prevent connection damage.

Abstract: A pipe connector has a rigid seal/support ring mounted on its pin. The pin has a nose and external threads extending rearward from the nose. The rigid seal/support ring is fixedly mounted on an exterior portion of the pin farther from the pin nose than the pin threads. The rigid seal/support ring is installed by a shrink- or press-fit and has a tapered exterior seal surface. The box has a rim and internal threads that mate with the external pin threads. The box has a seal surface for engaging the seal surface of the rigid seal/support ring to form an external seal. The box also has a seal surface to form an internal seal with the nose of the pin.

Abstract: A threaded joint for oil well pipes is provided which can guarantee a joint efficiency sufficient for practical use in deep wells, which has a decreased joint outer diameter, and which has an improved bending resistance, compression resistance, and over-torque resistance which are sufficient for use by the side track technique. It is an integral threaded joint for oil well pipes in which it has a joint efficiency of at least 70%, the outer diameter of the joint is larger than and at most 1.08 times the outer diameter of the oil well pipe bodies, and the threaded portions have a cross section of a trapezoidal shape with a load flank angle (&agr;) of the threads in the range of 0 to −20 degrees and a stabbing flank angle (&thgr;) thereof in the range of 35 to 50 degrees.

Abstract: A chemical conversion treatment liquid which can stably form a phosphate-type chemical conversion film on a steel material for a joint portion of an oil well steel pipe containing 0.5-13% Cr is developed. Using a chemical conversion treatment liquid to which a prescribed amount of potassium is added, a chemical conversion film containing a prescribed amount of potassium compounds and having a prescribed thickness can be formed on the threaded surface of a joint portion of an oil well steel pipe.

Abstract: A fatigue resistant waisted threaded tubular element for threaded tubular connection, and resulting threaded tubular connection. The threaded tubular element is waisted by a groove formed in the material beneath the threading to reduce the stiffness of the wall at the level of the first engaging threads. The groove can prevent an increase in the transfer of tensile loads at the level of the first engaging threads of the threaded element on which it is formed and on the corresponding last engaging threads of the mating threaded element intended to be connected thereto to form a threaded tubular connection. This improvement in load transfer limits the risk of initiating a fatigue crack in threaded tubular connections subjected to a cyclic load without reducing their static performances.

Abstract: A threaded metallic pipe for oil extraction industry has a threaded end portion with treated surface in which the metal surface has a roughness (Ra) comprised of 2.0 &mgr;m and 6.0 &mgr;m, which is covered by a uniform layer (7) of a dry corrosion inhibiting coating and a second uniform layer (8) of dry lubricant coating. Alternatively the layers (8, 9) combined into one uniform layer (9) of a dry corrosion inhibiting coating containing a dispersion of particles of solid lubricant.

Abstract: An elongated drive string assembly comprising a plurality of hollow sucker rods and a connecting elements with an axis, connected together and between a drive head located at the surface of an oil well and a rotary pump located deep down hole in an oil well. Each hollow sucker rod has at least a first end comprising an internal female threaded surface engaging an external male threaded surface on a connecting element, such as a nipple. In order to further optimize the stress distribution between the elements, frustro-conical, non-symmetrical threads with a differential diametral taper are used. The torque shoulders have a maximized mean diameter and cross-sectional area to resist storing reactive torque in the drive string. A modified nipple preferably has a small seal at its free end to decrease corrosion erosion problems. A modified rod may have a series of holes at each extreme end, to substantially increase the flow of fluid extracted.

Abstract: A threaded tubular connection has a box member including an internal thread, a pin member including an external thread engageable with the internal thread of the box member, and a protruding sealing surface disposed in the box member such that the pin member flexes radially inward upon passing the protruding sealing surface during make-up. The threaded tubular connection also has a recessed seal cavity disposed in the box member and a reverse angle shoulder at the pin nose that forces the pin member to flex radially outward into the recessed seal cavity of the box member upon final make-up.

Abstract: A threaded tube joint for oil extraction industry has a trapezoidal thread and a toroidal sealing surface (11) placed at its end near the thread and engages, for sealing, a corresponding frusto-conical sealing surface (12) wherein the toroidal sealing surface (11) has a radius Rs value comprised within the range given by the formula 1 E 2 ⁢ Vo ⁢ ( b 2.

Abstract: In a threaded joint for steel pipes comprising a pin and a box capable of mating with each other, the pin having an externally threaded portion and an unthreaded metal contact portion as a mating surface, and the box having an internally threaded portion and an unthreaded metal contact portion as a mating surface, the mating surface of at least one of the pin and the box is coated with a lower porous zinc or zinc alloy layer by blast plating and with an upper coating which is either a solid lubricating coating (comprising a lubricating powder in an organic or in organic binder) or a liquid, heavy metal powder-free coating (e.g., a liquid coating based on a highly basic organic acid metal salt such as a highly basic metal sulfonate).

Abstract: Connectors and connections that enhance mechanical and sealing engagement between the ends of tubular bodies that are radially expanded by a forging tool. The connectors are designed to maintain or restore mechanical and sealing engagement following expansion. The connections are made by joining components that exhibit different spring back characteristics following mechanical deformation. Dissimilar material may be used for the connectors or the connected components can be made of the same materials but dimensioned and configured to exert an interfering force between engaged components following expansion. In operation, a material or component with a high spring back characteristic is positioned adjacent a material or component having a lower spring back characteristic. Following passage of a forging tool, the expanded components spring back differently toward their original unexpanded dimensions to produce the enhanced seal or mechanical engagement.

Abstract: The threading of a threaded tubular element includes at least one tangential multiple radius junction zone at the thread root, in particular on the load flank side. This zone include a principal arc with a radius where the support circle cuts the flank at a point. The tangent to this circle makes a strictly positive angle with the flank. The secondary arcs have lower radii that effect the tangential junction of the principal arc on one side to the flank and on the other side to the thread root. The radius of the principal are larger than that of the standard circle which passes through and which would alone constitute a tangential junction zone. Such a threaded element provides a threaded tubular connection which incorporates good resistance to both static and cyclic stresses.

Abstract: A threaded joint for oil well pipes is provided which can guarantee a joint efficiency sufficient for practical use in deep wells, which has a decreased joint outer diameter, and which has an improved bending resistance, compression resistance, and over-torque resistance which are sufficient for use by the side track technique.

Abstract: A thread form for a tubular connection of the type having a pin member adapted to be made-up with a box member to form a pipe joint as shown. The pin member has pin threads with thread crests and thread roots which are adapted to be made-up with a mating box member having a complimentary thread structure. The pin thread crests are formed between a stab flank and a load flank of the pin thread. The pin thread has a multi-facited complex profile stab flank for engaging a mating stab flank on the complimentary box member to provide a wedging interfit between the surfaces of the pin and box threads. The pin and box threads are also helically structured as a wedge.

Abstract: The oilfield tubular pin and box connection includes double shoulders 16, 22. An inner sleeve 18 engages the box at shoulder 20, and provides one of the two shoulders 16, 22 for engaging the pin. The pin bore optionally may be provided with a similar sleeve 24, thereby providing one of the shoulders for engaging the box. The sleeve 18 may be secured to the box shortly after its manufacture, or may be added as a retrofit to an existing box with a single shoulder.

Abstract: A threaded joint to be expanded, including a lip at the end of the male element end a housing for the lip on the female element to make the threaded joint capable of being sealed and of having a maximum internal passage cross-section after being subjected to diametral expansion by more than 10%. The free male end surface is socketed before expansion into a partially transverse shoulder surface of the female housing through the matching rebating shapes of the surfaces. And, the male lip outer peripheral surface is arranged with little play of the internal peripheral surface of the female housing. Such a threaded joint is particularly useful for casings and tubings used in oil wells.