Abstract: A pipe joint comprising: a pin having a tapered male screw section formed on an outer circumferential face of an end of a pipe; a box having a tapered female screw section, which can be screwed to the tapered male screw section, formed on an inner circumferential face of an end of a pipe, wherein the tapered male screw section is screwed into the tapered female screw section, a top face of a male thread ridge of the tapered male screw section and a top face of a female thread ridge of the tapered female screw section have a predetermined width like a square screw thread, trapezoidal screw thread and buttress screw thread, and top faces of both thread ridges are inclined in a direction opposite to a tapered face of screw threads with respect to a face parallel to the pipe axis.

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 pipe joint formed by screwing a pin portion having a tapered male thread formed on the outer peripheral surface of the end of a pipe into a box portion having a tapered female thread formed on the inner peripheral surface of the end of a pipe or a short pipe so as to threadingly engage with the tapered male thread, the pipe joint having the following shape: clearance C between thread stab flanks: 0.5-1.0 mm thread stab flank angle &thgr;:  15-60 degrees thread crest surfaces and parallel to the pipe axis thread root surfaces: radius R of stab flank corner  1.0-1.25 mm portions of male thread: In addition, the taper of the incomplete thread portion of the pin portion is preferably 0.96-0.90 times the nominal taper of the complete thread portion.

Abstract: A locking tubing system includes a length of tubing lying in any geometric complexity including a substantially straight line and a first fitting body having a securing member rotationally locked thereto. The first fitting body is affixed to one end of the length of tubing. The system also includes a first nut having a plurality of openings in cooperative relation to engage the securing member, a second fitting body having a securing member rotationally locked thereto, the second fitting body is affixed to the other end of the length of tubing and a second nut having a plurality of openings in cooperative relation to engage the securing member. The first nut and the second nut are threaded onto corresponding mated fittings, each securing member being engaged with at least one of the openings of the respective nuts thereby locking each of the nuts to the respective fitting body.

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: Pipe integral threaded joint formed by a male element (1) and a female element (2) respectively placed on the external surface and on the internal surface of two truncated cone-shaped parts of the threading (6, 7, 8, 9) having the same conicity value and being radially spaced, both being respectively divided by annular shoulders (5, 5′) which are parallel and orthogonal with respect to the pipe axis. They are provided two sealing surfaces (12, 12′, 13, 13′), one of them being cone-shaped and the other being spherical. After the screwing of the two elements (1, 2) said two annular shoulders (5, 5′) are in contact. Each male (1) and female (2) element comprises, respectively along its external and internal surface, a circumference cavity (14, 15) placed between a part of the threading and the annular shoulder (5, 5′) in order to allow the expansion of the lubricating fat.

Abstract: A fitting for coupling a pump attachment to the inlet or discharge port of a pump or compressor has an annular body with an externally threaded nipple at one end and a circular flange at the other end. An axial aperture extends between the ends through openings at the nipple and the flange. The opening at the flange is internally threaded and begins at a recess in the flange. The threaded opening is of a standard ISO rated size complementary to the threaded nipple. A coupler kit is also disclosed having components to connect the device to the pump either in a mating flange connection using a hinge clamp or a threaded connection using a hose barb having a threaded end that threads into the opening in the fitting.

Abstract: A high strength Wedgethread Pipe Connection having a ratio of the radius change per turn to the thread width change per turn, as is required to maintain both a thread seal and tightness, even when the connection is subjected to transient service loads such as vibrations, shock, bending, tension, compression, torsion and/or thermal changes. The thread form may be Open or Trapped for use on large or small diameter pipe, configured such as: a flush joint; with collars of larger diameter than the pipe; with double-pin couplings; tool and accessory connections; or it may also be used to reversibly connect such as solid structural posts to base members where a wide range of repeatable makeup torque is desired. The threads have provisions for ease of manufacture and assembly, and to minimize handling damage.

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.

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: 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 guarantees galling resistance and gas tightness in a stable manner without application of a compound grease. A solid lubricating coating comprising a lubricating powder (e.g., molybdenum disulfide) and an organic or inorganic binder is formed on the contact surface of at least one of the pin and the box. The proportion of area of a cross section along the thickness of the solid lubricating coating which is occupied by secondary particles of the lubricating powder having an equivalent circular diameter of 15-60 &mgr;m is from 5-90%. Alternatively, the solid lubricating coating comprises, in addition to the lubricating powder, a fibrous filler (e.g., inorganic whiskers) in such an amount that the mass ratio of the fibrous filler to the binder is 0.01-0.5.

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. A method of forming a double flex seal for a tubular connection includes engaging an internal thread of a pin member with an external thread of a box member and flexing a pin nose of the pin member radially inward by passing the pin nose over a protruding sealing surface of the box member during make-up.

Abstract: A method of making up a pipe connection results in precise axial preload. The pipe connection has a box tubular member and a pin tubular member, each having mating threads and makeup shoulders. The designer determines a desired axial preload interference between the makeup shoulders. Based on this, the designer determines an increment of preload rotation required between the tubular members after initial contact of the makeup shoulders in order to achieve the desired axial preload interference. The tubular members are rotated relative to each other past the initial contact of the makeup shoulders for an amount equal to the increment of preload rotation determined.

Abstract: In a hydraulic joint structure for joining respective tubular joint portions of two members, opposed pressure-contact surfaces of the two members for preventing loosening form a downstream space on the downstream side of a seal member. A passage is formed on the pressure-contact surfaces in such a manner that when working fluid leaks from the upstream side of the seal member to the downstream space via a clearance between the seal member and the tubular joint portions, the passage permits the working fluid to flow from the downstream space to an external space in the state in which the pressure-contact surfaces are in pressure contact. The passage is formed in such a manner that the passage extends in a circumferential direction of the thread portions, and communicates at one end with the downstream space and at the other end with the external space.

Abstract: A thread for expandable downhole tubular connections is disclosed. It features a locking pattern on the pin and box, which engages upon expansion of the connection. The locking pattern compensates for longitudinal shrinkage away from a torque shoulder, as a result of expansion. A resilient seal can be incorporated into the design with pin to box clearance disappearing around the seal as a result of expansion. Resilient seals can be used in tandem to trap atmospheric pressure between them. The wellbore hydrostatic pressure helps engage the locking feature by pushing the box into the pin, helped by the trapped low pressure between the seals.

Abstract: A threaded pipe connection having box and pin members is provided with inner engageable thread means on the box and pin members, the thread means including a helical dove-tail thread having negative flank angles extending along the lengths of the box and pin members, and a helical intermediate thread having positive flank angles extending along the lengths of the box and pin members adjacent the dove-tail thread. Upon makeup, the intermediate threads generate hoop tension in the box member and hoop compression in the pin member, and the dove-tail threads generate hoop compression in the box member and hoop tension in the pin member.

Abstract: A high strength Wedgethread Pipe Connection having a ratio of the radius change per turn to the thread width change per turn, as is required to maintain both a thread seal and tightness, even when the connection is subjected to transient service loads such as vibrations, shock, bending, tension, compression, torsion and/or thermal changes. The thread form may be Open or Trapped for use on large or small diameter pipe, configured such as: a flush joint; with collars of larger diameter than the pipe; with double-pin couplings; tool and accessory connections; or it may also be used to reversibly connect such as solid structural posts to base members where a wide range of repeatable makeup torque is desired. The threads have provisions for ease of manufacture and assembly, and to minimize handling damage.

Abstract: A method of joining two pipe ends, by forming male threads on an end of a first pipe with a steep taper angle, forming matching female threads on an end of a second pipe, and applying adhesive material to the threads before twisting the pipes to fully engage the male and female threads, thereby spreading the adhesive material across adjacent load-bearing surfaces of the threads. The threads have multiple start locations for thread engagement so that the pipe ends may be twisted to achieve full engagement in less than one full relative rotation. The male and female threads are formed with a squeeze angle between matching surfaces of the threads between 0.5 and 5.0 degrees. The finished joint provides immediate leak-tightness, and immediate tensile, compressive and torsional strength and does not protrude outside of the pipe profile.

Abstract: Male and female coupling members (120, 130) for a drill string (10) have abutment faces (122, 132), fitted with torque reducing rings (124, 135) of low-friction, material, and multi-start threads (140, 150), with higher lead angles ∝ than forconvention coupling threads, to enable uncoupling of the coupling members (120, 130) at reduced torque.

Abstract: A radially expandable tubular connection including a box member having an internal thread and a first seal surface and a pin member having an external thread and a second seal surface. The external thread threadedly engages the internal thread and the first and second seal surfaces form a metal-to-metal seal upon engagement of the seal surfaces. At least one groove is formed on an outer surface of the box member, and the at least one groove is shaped so that the box member radially deforms in a direction toward the pin member in a region near the metal-to-metal seal after radial plastic expansion of the pin and box members after engagement of the threads.

Abstract: A screw-threaded joint for a pipe has a male portion (10) and a female portion (12), having complementary screw threads (11, 13). The male thread (11) extends to a position adjacent a complementary stop shoulder (18) on the female portion (12) having a recess of conical cross-section having a rounded apex. The recess is adapted to receive a head portion having a conical cross-section with a rounded apex, the radius of curvature of which is greater than that of the recess's apex providing a seal with improved stress dispersal properties upon application of torque. The wall (33) of the cone's in-use outwardly facing surface on the male portion (10) can subtend an angle of from 28-36° to the longitudinal axis of the pipe. The corresponding cone wall on the female portion can subtend an angle of from 28-38° with the same axis. The male portion (10) can comprise a second stress dispersing surface (41), concave in shape.

Abstract: The gap L (mm) which is the smaller of the gap L1 (mm) between the crest 1a of a tapered male thread 1 and the root 2b of a tapered female thread 2, and the gap L2 (mm) between the root 1c of the tapered male thread 1 and the crest 2c of the tapered female thread 2, the load flank angle &agr;(°) and the stab flank angle &bgr;(°), and the axial gap &dgr;(mm) which forms in the widthwise direction and is the difference between the thread ridge width of the tapered male thread 1 and the thread valley width of the tapered female thread 2 threadingly engaged therewith have the following relationship

Abstract: A pipe joint formed by screwing a pin portion having a tapered male thread formed on the outer peripheral surface of the end of a pipe into a box portion having a tapered female thread formed on the inner peripheral surface of the end of a pipe or a short pipe so as to threadingly engage with the tapered male thread, the pipe joint having the following shape: 1 clearance C between thread stab flanks: 0.5-1.0 mm thread stab flank angle &thgr;:  15-60 degrees thread crest surfaces and parallel to the pipe axis thread root surfaces: radius R of stab flank corner  1.0-1.

Abstract: The surface areas available for absorbing compressive loading of a threaded connection are increased by increasing the engaged area of a torque shoulder in the connection and by reducing the spacing between the stab flanks of the threads. The areas are increased by increasing the dimensions of the components and by decreasing the machine tolerances permitted in manufacturing the components. The gap in the connection adjacent the torque shoulder is reduced so that the contact surface area of the torque shoulder is increased while the close proximity of the surrounding cylindrical walls of the connection reduces voids that can receive plastic deformation of the torque shoulder corners. The surfaces adjacent the torque shoulder are cylindrical in shape rather than being tapered to reduce machining costs and increase the speed of manufacture of the connection.

Abstract: A lubricating coating composition in which at least one basic lubricant selected from a basic sulfonate, a basic salicylate, and a basic phenate is dissolved in a volatile solvent is applied to the frictional surface of a box and a pin constituting a threaded joint for oil well pipes. The composition may further contain one or more of a thermoplastic resin powder, another lubricant, and an extreme pressure agent. The surface roughness of the frictional surfaces preferably has an Rmax in the range of 5-40 micrometers.

Abstract: An adapter and coupler assembly has two externally threaded adapters, one left-hand threaded and the other right-hand threaded, and an internally threaded coupler, one end left-hand threaded, the other end right-hand threaded. The coupler threadedly engages the two adapters simultaneously, tightening on both by rotating in one direction, providing a fluid-tight seal. Each adapter has the other end barbed for connection to hose. The coupler and the two adapters each have an external annular flange which is perforated to receive seizing wire or wire ties to prevent the components from unthreading. The coupler has a multi-sided barrel at its center, and the adapters have a multi-sided nut portion, to provide purchase by a wrench-type tool. Each component may also have a mark indicating the starting point of the thread, to facilitate engagement of the components. The assembly is especially useful in fluid-carrying systems of boats, recreational vehicles, and campers.

Abstract: Several embodiments of a wedgethread pipe connection are disclosed that have improved makeup, sealing, and non-loosening characteristics. In one embodiment, an open wedgethread is disclosed that has an included angle measured in the gap between the stab flank and the load flank to be not less than zero, so as to prevent premature wedging between mating flanks before the position of full makeup is reached, as does occur between trapped wedgethreads wherein the included angle is less than zero. The invention may be used for pipe threads large or small, as a flush joint, with collars, screwed into plates or it may even be used to reversibly connect such as solid posts to base members where a wide makeup torque range is desired.

Abstract: During conditions of use of a threaded joint comprising a box portion and a pin portion used to threadingly join oil well pipes, the stress acting on the outer surface of the box portion is prevented from exceeding the yield strength of the base metal of the joint, and the occurrence of stress corrosion in the joint portion is prevented. Specifically, the amount of thread interference T is controlled to be at most a specified value calculated as a function of the inner diameter D1 of the pin portion, the thread effective diameter D2 at the basic diameter position, the outer diameter D3 of the box portion, the internal pressure Pi, and the yield strength &sgr;y and Young's modulus E of the base metal. As a result, a threaded joint which is suitable for joining of oil well pipes can be provided.

Abstract: A tightening method for a special joint having unthreaded metal-to-metal sealing surfaces and unthreaded shoulder portions. By controlling the ratio of the tightening torque at the completion of tightening to the shouldering torque at the time when the unthreaded shoulder portions come into contact to be in the range of 1.25-20 and more preferably 1.4-10, sufficient gastightness can be guaranteed and plastic deformation due to overtightening can be prevented regardless of the type of pipe joint or the conditions of use. As a result, it can be widely utilized in the tightening of special joints used with oil well pipes even under the present state of increasingly severe oil well environments.

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: 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. The nipple preferably has a wall cross-section that increases towards the torque shoulders from each free end, to increase fatigue resistance.

Abstract: A threaded union highly resistant to overtorque and compression that includes a threaded member in its internal surface—called female—that joins a threaded member in its external surface—called male—. The union between the male extreme and the female is produced through the threaded surface. When the members are fully assembled, one axially oriented surface in the free extreme of one of the members—called nose—presses against a corresponding surface in the other member—called shoulder of torque. This shoulder is comprised of two surfaces, a first one coincidentally oriented to the corresponding nose of the first member, and a second one truncated and conical in shape with an angle B and with the axis of the pipe located between the first surface and the internal cylindrical surface of the female member.

Abstract: A threaded connection for tubular members comprising a box connector having axially spaced threaded sections and a thread-free section therebetween, the threaded sections of the box connector defining a two-step thread, a pin connector having axially spaced threaded sections and a thread-free section therebetween, the threads in the box connector mating with the threads on the pin connector, there being at least one annular relief in the thread-free portion of at least one of the pin connector and the box connector, an axially facing pin torque shoulder being formed on the pin connector and an axially facing box torque shoulder being formed on the box connector, a metal-to-metal seal being formed between the thread-free sections of the pin and box connectors when the pin torque shoulder and the box torque shoulder are engaged, the annular relief being adjacent the metal-to-metal seal.

Abstract: A radially expandable tubular connection including a box member having an internal thread and a first seal surface and a pin member having an external thread and a second seal surface. The external thread threadedly engages the internal thread and the first and second seal surfaces form a metal-to-metal seal upon engagement of the seal surfaces. At least one groove is formed on an outer surface of the box member, and the at least one groove is shaped so that the box member radially deforms in a direction toward the pin member in a region near the metal-to-metal seal after radial plastic expansion of the pin and box members after engagement of the threads.

Abstract: The invention concerns a male threaded joint (1) tipped with a male lip (18) having a male seating face (13) and a male stop (14) transverse surface (16) proximate to the male seating face; and a female threaded element (21) comprising, for co-operation with the corresponding means of the male threaded element a female seating face (23) and a female stop transverse surface provided on a female shoulder and proximate to the female seating face. The annular female shoulder zone (24) which is subjected to axial compression forces resulting from the pressure of the male (16) and female (26) stop surfaces have an inner peripheral surface (27) whereof the diameter (IDB) is at least locally proximate to said female stop surface (26) smaller than the diameter (IDP) of the inner peripheral surface (17) of the male lip (18), the ratio R of said two diameters (IDB/IDP) being less than 1 but not less than 0.9.

Abstract: The joint for the connection of fibre-reinforced composite pipes comprises a male part and a female part provided on two end parts of pipe to be connected, the male part and the female part have an axial modulus of elasticity which substantially increases proportionally from their free ends to their connection with the pipes.

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: A threaded connector includes a pin member having a large thread step and a small thread step. The pin member has a first sealing surface between the steps. Threads on the steps of the pin member each have load flanks and stab flanks. The connector includes a box member having a large thread step and a small thread step corresponding to the thread steps on the pin member. The box member has a second sealing surface corresponding to the first sealing surface. Threads on the steps of the box member have load flanks and stab flanks corresponding to the threads on the pin member. The threads on the large thread step have a first clearance between corresponding stab flanks on the pin and box members when the pin and box members are assembled and the corresponding load flanks are engaged. The threads on the small step have a second clearance between corresponding stab flanks when the pin and box members are assembled. The first clearance in one embodiment is smaller than the second clearance.

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 pipe connector having a pin element having a tapered outer threaded section between an external shoulder and a pin end face, a first threadless pin section between the external shoulder and the outer threaded section, and a second threadless pin section between the outer threaded section and the pin end face. Provided for threaded engagement with the pin element is a box element having a tapered inner threaded section between an internal shoulder and a box end face, a first threadless box section between the internal shoulder and the inner threaded section, and a second threadless box section between the inner threaded section and the box end face. Suitably, the second threadless pin section and the first threadless box section in the area of the internal joint is at least twice as long as the first threadless pin section and the second threadless box section in the area of the external joint.

Abstract: A pipe connector for offshore risers has conical thread forms. The connector has a pin with a nose, an external shoulder, and conical first and second pin threaded sections. The first and second pin threaded sections are axially separated by a pin intermediate section that is free of threads. The first and second pin threaded sections are formed on a single continuous taper and on a continuous helix. The intermediate section is also conical and at the same taper as the pin first and second threaded sections. The connecter has a box with a rim, an internal base, and a conical receptacle between the rim and the base. The conical receptacle has first and second box threaded sections that make up with the pin threaded sections. The box also has an intermediate section between its first and second threaded connections that is free of threads. The intermediate sections make up with radial interference. Upper and lower metal-to-metal sealing surfaces are located at the nose and at the base of the pin.

Abstract: A connector for connecting large tubulars of the type used in oil well tubing, casing and the like, without resorting to welding, to form a pipe string for use in drilling. The connector comprises a pin and box threaded connection having guiding surfaces integral with the pin and box members to facilitate the threaded connection of large tubulars. Alignment indicators may be used to provide that initial thread contact is near 360° around the circumference of the connector to provide a more even distribution of the initial contact forces on the threads rather than substantially all force acting on a smaller area of thread. This alignment also speeds the makeup of the pipe. A thread factor is provided with a desired axial length and radial length to avoid deformation of the threads. The tubular alignment using alignment indicators, centralizing effect of guidance surfaces, and thread factor may work in combination to improve the reliability, durability, and speed of making the connection.

Abstract: A threaded connection for two metal pipes including a male element at the end of a first pipe and a female element at the end of a second pipe, the male element including a male external thread, the female element including a female internal thread. The male and female threads are screwed one into the other. At least one of the male or female threads includes a groove formed in the thread and opening either into a stabbing flank or into a crest of the thread or straddling the stabbing flank and the thread crest. The groove is disposed in the thread so as to increase the flexibility of the portion of the thread which comes into pressure contact with the mating thread or to reduce the contact surfaces or to affect the two aspects at the same time.

Abstract: An apparatus, system, and method of axially joining a first and second member having externally threaded ends without having to turn either member. The set of external threads of the first and second members are wound in a predetermined direction and are located on a first member end and a second member end respectively. In one aspect, the invention is three-piece apparatus comprising a coupling, a reverse, and an adapter.

Abstract: An offshore riser includes a plurality of tubular elements, each having a pin member on one end and a box member on the other end for connection with adjacent tubular elements. The pin member has an external thread which engages an internal thread on the box member of the adjacent tubular element. A dual angle torque shoulder locks the box end securely into place against the pin, preventing radial distention of the box end and maintaining bearing pressure between the external sealing surfaces. Also, stress relief grooves are located on the box member and on the pin member, to reduce the incidence of stress fractures, thereby improving the fatigue life of the connection.

Abstract: The roots of the box threads in a drill collar or heavyweight drill pipe are configured to reduce the connection stresses encountered during drilling and makeup of the connection. The thread root design in the box reduces fatigue damage caused by makeup torque and cyclic stressing of the engaged drill string connection as it is rotated around curved sections of the well bore. A conventional V-type thread form in the box is provided with an enlarged root radius having its center point offset from the centerline of the opposing thread flanks. The load flank of the thread tangentially engages the arc of the root. The stab flank of the thread is intersected by the enlarged root radius extending to a flat intersecting surface that may extend as far up as the thread pitch diameter.

Abstract: A modular shower arm mounting system includes a water conduit and a replaceable shower arm assembly in sealing engagement therewith. The water conduit has a generally uniform inner wall and an outer diameter wall having a hexagonally or polygonally shaped drive force receiving area adjacent a threaded area. The conduit has one end attached to a manifold behind a shower wall surface and an outlet end projecting from the wall surface of sufficient length therefrom so that the drive force receiving area and threaded area are spaced from the wall surface. The replaceable shower arm assembly has an inner wall with a threaded portion for engagement with the conduit and a substantially smooth portion of gradually decreasing inner diameter downstream of said threaded portion approaching an outwardly projecting end thereof. The seal ring is adjacent the outlet end of the conduit to form a seal with the assembly.

Abstract: An oil-country-tubular threaded joint can withstand tensile forces, and in addition, other forces such as compression and bending forces, thus producing highly improved characteristics in regard to the prevention of fluid leakage. The oil-country-tubular threaded joint is formed of male screw threads and female screw threads which have a load face whose load flank angles are in a range of −3° to −25°, in which the load flank angles are varied at a position at which the load face is divided in the height direction of the male screw thread into an upper side and a lower side so that an upper load flank angle is smaller than a lower load flank angle by 0.5° to 2.0°. Also, a thread-machining apparatus for the oil-country-tubular threaded joint uses chasers having cutting edges which are shaped so as to correspond to thread shapes for machining screw threads whose flank angles are partly of negative values for the oil-country-tubular threaded joint.

Abstract: An oilfield tubular member 10 includes pin member 12 and box member 14 each having a tapered thread 18, 20, 70, 72. The pin thread 18 has a root 28, a crest 26, a pressure flank 34 and stab flank 36. The box thread has root 32, a crest 30, a pressure flank 84 and stab flank 86. The pin crest 26 has a stab flank pin crest radius 40 and a pressure flank pin crust radius 38 which is at least twice the radius 40. The improved oilfield connection minimizes damage to the connection during misalignment of the pin member and box member.

Abstract: Several embodiments of a wedgethread pipe connection are disclosed that have improved makeup, sealing and non-loosening characteristics. In one embodiment, an open wedgethread is disclosed that has an included angle measured in the gap between the stab flank and the load flank to be not less than zero, so as to prevent premature wedging between mating flanks before the position of full makeup is reached, as does occur between trapped wedgethreads wherein the included angle is less than zero.