Abstract: A threaded connection including first and second tubular components configured for exploration or operating a hydrocarbon well; the first tubular component including an external abutment, a male threaded connection portion extended by a non-threaded terminal portion defining an internal abutment at its axial end; the second tubular component including a female end defining at a free end a bearing surface forced against the external abutment, a female threaded connection portion made up with the male threaded connection portion and terminating in an internal shoulder forced against the internal abutment, an initial non-threaded portion connecting the female threaded connection portion to the internal shoulder, which includes a maximum radial interference locally forming a sealing surface located between the male threaded connection portion and the internal abutment, and located at a non-zero distance from the internal abutment, the distance being more than half of an axial distance of the terminal portion.

Abstract: The dual-threaded screw structure 1 has a first thread (S1) and a second thread (S2) with various leads formed on the dual-thread portion and has a function of preventing loosening without insufficiency in strength of the dual-thread portion. This dual-thread portion is composed of a first thread (S1) consisting of a coarse thread with a standard pitch P and a specific second thread (S2). The second thread (S2) is formed continuously on the thread ridge of the first thread (S1). The second thread (S2) has a sectional shape of this thread groove same as or substantially same as the first thread (S1), has a same twisting direction as the first thread (S1) and is a multi-threaded thread having threads with a triangular sectional shape and having a lead (L=n*P) a determined number (n)-times of a standard pitch P.

Abstract: A casing collar locator including a housing having a first end, a second end, and a passage extending between the first end and the second end, a first cylindrical member having a passage extending therethrough and coupled to the first end of the housing, and a second cylindrical member having a passage extending therethrough and coupled to the second end of the housing, and a coil assembly disposed in the passage of the housing and configured to produce an electrical signal in response to a change in a magnetic field, wherein the coil assembly comprises an annular magnet having a diameter greater than an axial width of the annular magnet.

Abstract: A threaded joint for steel pipe is provided that ensures good sealing performance and reduces crevice corrosion. A threaded joint includes a pin (10) and a box (20). The pin (10) includes a first shoulder surface (11), a first male thread (14), a second shoulder surface (18), and a second male thread (17). The box (20) includes a first shoulder surface (21), a first female thread (24), a second shoulder surface (28), and a second female thread (27). Supposing that the distance between the shoulder surfaces of the pin (10) is represented as Lpin and the distance between the shoulder surfaces of the box (20) is represented as Lbox, and the interference ?shld is defined by Equation (1) given below, then, the threaded joint is constructed such that Equations (2) and (3) given below are satisfied.

Abstract: A threaded joint is constructed of a pin and a box. The pin includes, in order from a tubular body having the pin toward the free end thereof: a male threaded portion and a lip portion including a sealing surface. The box includes: a female threaded portion corresponding to the male threaded portion of the pin; and a recessed portion corresponding to the lip portion, the recessed portion including a sealing surface. The lip portion includes, in order from a male threaded portion toward the free end of the pin: a neck portion; and a sealing head portion including the sealing surface. The maximum outside diameter of the region of the sealing surface in the sealing head portion is larger than an outside diameter of the neck portion at a boundary between the neck portion and the male threaded portion.

Abstract: An example threaded connection includes first component and a second component. The first component may have a first outer diameter, a first threaded portion at or near the first outer diameter, and an end portion. The second component have may a second outer diameter a second outer diameter greater than the first outer diameter; a second threaded portion, at least one of the first or second sets of threads having at least one of a variable pitch and a variable taper; and an internal shoulder positioned to contact the end portion of the first component when the first threaded portion are engaged with the second threaded portion. A connection ring may be coupled to the second component and positioned to engage with a portion of the first component when the first component is positioned within the second component.

Abstract: A connection is established between a pin connector and a box connector defined on a pair of tubular members such as casing segments in the field of oil and gas recovery. The pin connector and box connector include features for the protection of metallic-sealing surfaces during assembly, disassembly, transport and handling of the tubular members. The pin connector includes a stabbing flank with an inwardly tapered annular flank surface thereon, and an alignment protrusion extending outward with respect to the pin-side metallic sealing surface in a direction normal to a cone angle defined by the inwardly tapered annular flank surface. The alignment protrusion engages internal surfaces of the box connector to concentrically align the pin connector with the box connector, and thereby protects the metallic sealing surfaces from damage that might otherwise result from collisions between the pin connector and the box connector.

Abstract: A threaded joint is constructed of a pin and a box, the box having an outside diameter less than 104% of an outside diameter of a tubular body having the pin. The box includes, in order from an end of the box toward the tubular body: a lip portion and a female threaded portion, the lip portion including a shoulder surface and a sealing surface. The pin includes a shoulder surface, a sealing surface, and a male threaded portion. The lip portion of the box has a nose portion disposed between the shoulder surface and the sealing surface and an annular portion disposed between the sealing surface and the female threaded portion. The nose portion and the annular portion are not in contact with the pin, and a length of the annular portion is longer than a thread pitch of the female threaded portion.

Abstract: Stand-alone interbody fusion devices and corpectomy devices suitable for use with an oblique implantation. The stand-alone interbody fusion devices may include a spacer having a substantially U-shaped body and a plate coupled to the spacer. The overall shape of the implant is asymmetrical such that a median plane, an oblique plane, or both planes divide the spacer and the plate into two asymmetrical halves. The implants are shaped and configured to allow for an oblique or anterolateral approach to the spine or an oblique corpectomy.

Abstract: Open implant closure structures include a helically wound guide and advancement flange form having splay control surfaces. Multi-start closures and closures with inner set screws have splay control contours for interlocking with cooperating flange forms of bone anchor receivers. Flange form heights, thicknesses and other geometry, such as splay control ramp angle may be varied.

Abstract: A threaded joint is adapted for tubes where the stress or the strain concentration hardly occur at a threaded corner portion of box side even when the threaded joint receives repeated tensile-compressive forces or repeated bending forces. In a radial seal type threaded joint, tensile efficiency TE (%) defined by a ratio Sc/Sp between a cross-sectional area Sc, an area of Critical Cross Section (CCS) including a portion where a tensile stress and a strain become the highest in a tube circumferential cross section of a box and a cross-sectional area Sp of a tube body satisfies formula TE (%)?2.25×t/?+99.9 having a ratio t/? between an internal thread height t of the box and a radius of curvature ? of a corner portion of internally-threaded bottom load surface side.

Abstract: A threaded joint is constructed of a pin and a box. The pin includes a shoulder surface, a seal surface, and a male threaded portion. The box includes a shoulder surface, a seal surface, and a female threaded portion. The male threaded portion and the female threaded portion are each a tapered threaded portion including threads having a trapezoidal profile. The male threaded portion has a width of the threads that gradually decreases along the thread helix and a width of grooves that gradually increases along the thread helix. The female threaded portion has a width of grooves that gradually decreases along the thread helix and a width of the threads that gradually increases along the thread helix.

Abstract: A threaded tubular connection including a first tube and a second tube is provided. The first tube includes a pin member which extends from an end of a main body of the first tube to a terminal end of the first tube. The second tube includes a box member which extends from an end of a main body of the second tube to a terminal end of the second tube. A cross-sectional area of a pin critical cross-section is within approximately ±5% of cross-sectional area of a box critical cross-section of the box member. The cross-sectional areas of each of the pin and box critical cross-sections are within approximately ±5% of the sum of the cross-sectional areas of a box intermediate critical cross-section of the box member and a pin intermediate critical cross-section of the pin member.

Abstract: A threaded joint in which the outer peripheral face of the pin nose has a single tapered shape, the seal face of the box has an outwardly convex curved shape, and a seal point xp defined by equation (1) is greater than or equal to 0.2 inches, x p = ? x 1 x 2 ? p ? ? x ? ? d ? ? x F ? ? F = ? x 1 x 2 ? p ? ? d ? ? x ( 1 ) where p is a contact face pressure, x is a distance from an end of the pin in a pipe axis direction, and x1 and x2 are respectively a lower limit and an upper limit of a domain of x corresponding to the seal portion.

Abstract: A thread structure in accordance to one or more embodiments includes a thread extending helically along the cylindrical member in spaced thread turns, the thread having a crest extending between a first flank and a second flank and a root extending between the thread turns, the root having a curvature defined by a portion of an ellipse tangentially adjoining the first and second flank at respective flank transition points, the ellipse having a major axis extending parallel to the axis and a minor axis extending perpendicular to the major axis and through a root bottom.

Abstract: A threaded tubular connection including a first tube and a second tube is provided. The first tube includes a pin member which extends from an end of a main body of the first tube to a terminal end of the first tube. The second tube includes a box member which extends from an end of a main body of the second tube to a terminal end of the second tube. A cross-sectional area of a pin critical cross-section is within approximately ±5% of cross-sectional area of a box critical cross-section of the box member. The cross-sectional areas of each of the pin and box critical cross-sections are within approximately ±5% of the sum of the cross-sectional areas of a box intermediate critical cross-section of the box member and a pin intermediate critical cross-section of the pin member.

Abstract: In a joint for oil country tubular goods, a pitch change is made such that an internally-thread pitch has the same value as an externally-thread pitch from a thread end portion on a box end side to a pitch change position taken on a box center side with respect to a position away from the thread end portion by ½ of an entire length of the threaded portion, and the internally-thread pitch is changed to a value less than the externally-thread pitch at the pitch change position so that a thread gap is gradually decreased from the pitch change position to a position of the thread end portion on the box center side, and the thread gap is eventually set to a value which is 0.2 to 0.8 times as large as the thread gap before the pitch change is made.

Abstract: A medical connector includes a body having a distal end, a proximal end, and a sidewall extending between the distal end and the proximal end, a helical thread extending radially outward from a surface of the sidewall and comprising a crest portion, flank portions, and a root portion with the flank portions connecting the root portion to the crest portion, and at least one micro-thread extending radially outward from the surface of the sidewall. At least a portion of the micro-thread is spaced apart from the helical thread.

Abstract: In a screw joint for a steel pipe, a taper angle of a tapered surface of a pin is substantially the same as a taper angle of a tapered surface of a box. In addition, the pin and the box interfere with each other in a radial direction while a seal surface of the pin and a seal surface of the box contact each other in a process of make-up between a male screw portion and a female screw portion, and at least apart of the seal surface of the pin comes into close contact with at least a part of the seal surface of the box over the entire circumference. Moreover, a contact pressure amplification mechanism, which increases a contact pressure between the seal surface of the pin and the seal surface of the box at the completion of the make-up, is further provided.

Abstract: A tubular member has a longitudinal axis, a first end, and a second end. The tubular member includes a pin connector including an external shoulder, an internal shoulder axially spaced from the external shoulder, and a plurality of threads in a region between the external shoulder and the internal shoulder that taper relative to the longitudinal axis at 1.0 to 1.5 inches per foot. The threads include an axial density measured in a number of threads per inch (TPI), and when the pin connector is threadably engaged with a box connector, each of the threads contacts a corresponding box thread on the box connector along a projected radial distance HC. In addition, the threads are configured such that the product of 2(?{square root over (3)})(HC)(TPI) is greater than or equal to 0.95 and less than or equal to 1.05.

Abstract: A connection structure between a pipe body and a joint of an aluminum alloy drill pipe is provided, and the connection structure comprises a first joint provided with an internal thread section, wherein an internal thread tooth bottom of the internal thread section is an inclined surface; and a second joint provided with an external thread section which is able to be fitted with the internal thread section and has threads of a complete tooth shape, a tooth height of the external thread section being larger than that of the internal thread section. The internal thread tooth bottom is designed as an inclined surface such that an external thread tooth crest is squeezed against the internal thread tooth bottom and plastically deformed along the inclined surface of the tooth bottom during an engagement, so that the engaged threads are self locked to effectively prevent the loosing of the engaged threads.

Abstract: A threaded connection includes a first tube having a pin, the pin having pin threads, a circumferential concave outer pin surface, and a pin torque shoulder at a free end, the concave outer pin surface including a pin seal surface and a continuous extension from the pin seal surface to the pin torque shoulder. A second tube has a box, the box has box threads for interacting with the pin threads, a circumferential inner box surface and a box torque shoulder. The inner box surface has a radially inwardly extending box seal surface, the pin seal surface contacts the box seal surface to define a seal. The seal is spaced from the free end when the pin and box torque shoulders contact, the continuous extension continuing from the seal to the pin torque shoulder. A method for making-up a threaded connection is also provided.

Abstract: A premium threaded joint has a pin-side shoulder angle ?1, a box-side shoulder angle ?2, a seal interference quantity ? and a seal point distance xp satisfying ?2??1=?×?/xp, ?=7 to 14, and a pin distal end thickness tp1 defined by a difference Re?Ri between a radius Re of a pin most distal end portion and an inner radius Ri of a pin distal end portion is 0.25 times or more as large as a pin raw pipe thickness tp0.

Abstract: A tubular connection, method for connecting tubulars, and a coupler for connecting together tubulars, of which the tubular connection includes an inner body including a bore, external threads, a tapered torque nose, and a radially-facing sealing surface. The connection also includes an outer body including a bore in communication with the bore of the inner body, internal threads configured to engage the external threads of the inner body, a tapered torque-stop surface that engages the tapered torque nose, and a radially-facing sealing surface that forms a seal with the radially-facing sealing surface of the inner body. The external threads, the internal threads, or both include at least one kick-out feature including at least one rounded or chamfered corner thereof.

Abstract: A gap sub assembly and methods for using the gap sub provide an electrical isolating joint that is mechanically strong enough to withstand the rigors of drilling environments, resistant to environmental effects (heat, corrosive liquids and gases, and high pressures), and maintainable. The gap sub assembly provides a male member and a female member that may be connected together, wherein a non-conductive material is applied between the two at the attachment points. A locking ring or collar affixes to both male and female members to prevent back off while drilling and preserving the electrical isolation of the gap joint. Non-conductive material may be injected between the locking ring and one or more of the male or female members.

Abstract: A female component for a tubular hydrocarbon working string subjected to dynamic bending strength includes a tapered female threading cooperating with a male threading to form a rigid mutual connection of tubular elements, a free end and female sealing surface disposed between the free end and the female threading, the female sealing surface to contact in a made up condition with a male sealing surface to form a metal-metal seal, and an annular groove provided between the free end and the female sealing surface, leaving an axial distance greater than zero between the free end and a transition region outwardly of the female sealing surface, and a radial distance greater than zero between the female sealing surface and a chamfer at the free end, the groove including borders formed by the chamfer and a portion of the transition region protecting the female sealing surface prior to makeup.

Abstract: Drill string components having at least two threads extending around a body. The leading end of each thread can have a configuration having increased strength and resistance to jamming and cross-threading. In particular, the leading end of each thread can comprise a planar surface normal to the body. The leading end of each thread can provide an abrupt transition to full thread depth that helps reduce or eliminate cross-threading and can be oriented at an angle relative to the axis of the drill string component. Each thread can further provide at least one of a variable thread width and a variable thread pitch configured to create an axial progressive fit. Each thread can also provide a cylindrical thread root and a thread crest that circumscribes a frusta-cone over at least a portion of the axial length of the threads configured to create a radial progressive fit.

Abstract: A tubular component for a threaded connection includes at one of its ends a threaded zone. The end includes a terminal surface and the threaded zone includes, over at least a portion, threads including, when viewed in a longitudinal section passing through an axis of the tubular component, a thread crest, a thread root, a load flank, and a stabbing flank, such that a respective axial width of thread crests decreases in a direction of the terminal surface while a respective axial width of thread roots increases when considered in the same direction. At least one of a profile of the load flank and a profile of the stabbing flank of a thread portion includes, as a contral portion, a continuous curve provided with a point of inflection such that the profile with the point of inflection in convex at the thread crest and concave close to the thread root.

Abstract: In a method for influencing the thread geometry of an internal thread of a first component of an injection device for internal combustion engines, which is provided for carrying high-pressure fluid, wherein the first component has a tubular end portion and an internal thread is formed on the interior surface of the tubular end portion, and a second component having an exterior surface on at least a portion thereof so as to be received in the tubular end portion of the first component wherein the exterior surface is threaded so said second component can be screwed and clamped against a support surface of the first component, and wherein the tubular end portion on the external side is acted upon by a radial compression force allowing a plastic deformation. The tubular end portion is transformed thereby in such a manner that the internal thread obtains an inner diameter (D) continuously decreasing towards the free end.

Abstract: A method of opening an orifice in a downhole article includes forming a downhole article having an orifice, the orifice having a selectively removable plug sealingly disposed therein, the selectively removable plug comprising a selectively removable plug body formed of a plug body material and a selectively removable sealant coating formed of a coating material disposed on an outer surface of the plug body. The method also includes disposing the article within a wellbore. The method further includes exposing the selectively removable plug to a first wellbore fluid that is configured to selectively remove the sealant coating and provide a fluid access to the plug body. The method further includes exposing the selectively removable plug body to a second wellbore fluid through the fluid access that is configured to selectively remove the plug body and using the second wellbore fluid to break the sealant coating into a plurality of pieces.

Abstract: A coupling including a tubular body with two ends of the body each including a portion of internal threading for joining to a tubular element, and a central portion separating the two ends each including a portion of threading and having a wall thickness greater than the wall thickness of the ends of the body. The coupling includes an extension segment that extends from one of the ends of the tubular body, after the portion of internal threading, the extension segment having same outside diameter as that of the tubular body and an inside diameter greater than or equal to that of the portion of internal threading. Moreover, the extension segment includes a housing, including an opening onto an external surface of the coupling, in which an electronically responsive identification tag is housed.

Abstract: Various identification tags are disclosed. In one embodiment, a system includes a coupling with an extended skirt having an opening to receive an identification tag. The identification tag may be configured to be snapped into the opening, slid into the opening, or threaded into the opening, for example. The identification tag, such as an RFID tag, may include an electronics module to enable wireless communication with a reader. The electronics module may be received within a body to facilitate installation and retention of the tag and increase durability. The disclosed tags may also be installed in other components. Various other tags, systems, devices, and methods pertaining to identification tags are also disclosed.

Abstract: A riser joint connection includes a box connector having a box preload fixture, a pin connector having a pin preload fixture, at least one shear element configured to fit into at least one shear element cavity defined by a box connector shear groove in alignment with a pin connector shear groove, wherein the at least one shear element contacts load surfaces of the pin connector and the box connector.

Abstract: An apparatus is disclosed that forms a piping thread form of four threads per inch pipe (TPI). The thread form is configured to have a load flank, a load flank angle, a stab flank, a stab flank angle, a crest, and a root. Hydrostatic pressure tests using the 4-round thread form at pressures of 4,500 psi and greater resulted in failures due to thread leaks. Tensile tests using the 4-round thread form at loads of 187,400 lbs. and greater resulted in shearing at forces of 3,535 psi and greater.

Abstract: A tubular connection, method for connecting tubulars, and a coupler for connecting together tubulars, of which the tubular connection includes an inner body including a bore, external threads, a tapered torque nose, and a radially-facing sealing surface. The connection also includes an outer body including a bore in communication with the bore of the inner body, internal threads configured to engage the external threads of the inner body, a tapered torque-stop surface that engages the tapered torque nose, and a radially-facing sealing surface that forms a seal with the radially-facing sealing surface of the inner body. The external threads, the internal threads, or both include at least one kick-out feature including at least one rounded or chamfered corner thereof.

Abstract: A threaded joint for steel pipes that includes a pin and a box. The pin has an externally threaded portion, a nose, and a shoulder portion. The box has an internally threaded portion, a sealing surface, and a shoulder portion. The outer circumferential surface of the nose of the pin has an outward convex curved shape, and the sealing surface of the box has a tapered shape. Additionally, the cross-sectional area of the pin at a seal point is 35% or more of the cross-sectional area of an original pipe portion corresponding to an unprocessed portion of the pin, the seal point being a portion on the pin that first comes into contact with the sealing surface of the box when the pin and the box are joined.

Abstract: A device in a drill string component for percussive rock drilling including a thread for threading together with another drill string component including a complementary thread. The thread includes a thread groove formed by two thread flanks and an intermediate thread bottom. In operation one of the flanks forms a pressure flank. The thread groove has an essentially equally shaped sectional form along its axial extension. The thread bottom exhibits at least three surface portions with part-circular shape, as seen in an axial section. The surface portions with part-circular shape have increasing radiuses, as seen from each thread flank to an intermediate surface portion of the thread bottom. Also a thread joint and a drill string component.

Abstract: A method and apparatus for joining first and second bodies coaxially together to resist relative axial and rotational movement between the bodies. A male portion of the first body is received in a complementary female portion of the second body, and the male and female portions are aligned axially on a common axis such that respective cooperating grooves in opposing cylindrical or tapered complementary surfaces of the male and female portions are aligned to form a plurality of passageways or a passageway having a plurality of passageway portions, between the opposing cylindrical or tapered complementary surfaces. At least two of the passageways or at least two of the passageway portions are disposed at different angles to the common axis.

Abstract: A threaded joint for steel pipes comprising a pin (1) and a box (2). The pin has a male thread (11) and a lip (12) which comprises (i) a sealing surface (13) and (ii) a nose portion (16) provided with a shoulder surface. The box has a female thread (21), a sealing surface (23) and a shoulder surface. The shoulder surface of the pin comprises two distinct adjacent surfaces, main shoulder (14) in the inner side and sub shoulder (15) in the outer side. Correspondingly, the shoulder surface of the box comprises two distinct adjacent surfaces, main shoulder (24) in the inner side and sub shoulder (25) in the outer side. The main shoulder surfaces of the pin and box are disposed such as to prevent a radially inward deformation of the lip end, and the sub shoulder surfaces of pin and box are disposed such as to limit a radially outward deformation of the lip end.

Abstract: A coating system component which may be used to be wetted and/or flown through at least in some sections by a coating agent. The component may include a fastening base and at least one holding part which is arranged on the fastening base for being fastened to or in a coating system device. The holding part may be an external thread having a special configuration in order to meet the special requirements of painting facilities, according to various exemplary illustrations. Furthermore, a corresponding coating system device may be provided, to which the coating system component can be fastened in a detachable manner.

Abstract: A metal-to-metal sealing system connecting first and second tubular members includes a first seal configuration on the first tubular member and a second seal configuration on the second tubular member. The first seal configuration includes a first annular groove and a first annular tooth, and the second seal configuration includes a second annular groove and a second annular tooth. The second annular tooth is positioned within the first annular groove with the second annular tooth face engaging the first annular shoulder face to define a first shoulder. The first annular tooth is positioned within the second annular groove with the first annular tooth face engaging the second annular shoulder face to define a second shoulder. Locations of primary sealing contact of surfaces of the members are spaced axially away from the first and second shoulders.

Abstract: Threaded couplings and methods for use in drilling with casing can include first and second male members having exterior threads engaged with interior threads of a female member. Exterior shoulders of the male members can abut interior shoulders of the female member to facilitate placement of the male members such that pin noses thereof are positioned at the center of the female member, where abutment between the pin noses of the male members can form a seal. The shoulders can be provided with negative angles to prevent disengagement. Tapered surfaces can be provided on the male members, to contact tapered surfaces on the female member to form metal-to-metal seals for enhancing the integrity of the connection, a straight thread configuration can be used to maximize the thickness of the coupling, and bearing journals or guides can be used to facilitate engagement of the threads and retention of the engagement.

Abstract: A pipeline includes a pair of pipe sections with ends (20, 22), connected together by threads. the pipe ends having axial and radial abutments lying beyond the ends of the thread. The abutments are located to stabilize a nib sealing arrangement and to enhance the capacity to resist bending while using a shorter thread length. The shorter threads (24, 26) enable pipe ends of smaller wall thicknesses to be used. At the abutments, each pipe end has a nib (40A, 40B) that is deflected to enter a groove as the pipe ends mate.

Abstract: Assemblies that can be disposed in a subterranean bore and that can facilitate branch wellbore creation are described. An assembly can include threadedly coupled components having inner and outer sealing members in grooves. The sealing member can cooperate with the components to provide a pressure seal. The assembly can also include a venting member for equalizing pressure in a chamber defined by the coupled components. One of the components can be made from aluminum. At least part of that component can be coated with a coating material that is nonconductive.

Abstract: A retaining device for a threaded connection that is expanded holds the connection together to prevent leakage. In a two step thread the retention device is located between the steps and comprises a nose in a groove that holds aligned surfaces together for a metal to metal connection and allows for relative axial movement at the same time.

Abstract: A set for obtaining a threaded connection used in hydrocarbon wells includes a first tubular component, a second tubular component, and a third tubular component. A threaded zone provided on an internal circumferential surface of an end of the third component cooperates by makeup with one of two threaded zones of an end of the first component. A threaded zone provided on an external circumferential surface of the end of the third component cooperates by makeup with one of two threaded zones of the second component. The second and third components define an end of makeup of the threaded zones. The other threaded zone provided on the end of the first component cooperates by makeup with the other threaded zone provided on the second component.

Abstract: A threaded connector including female thread and male thread. The female thread is symmetrically disposed on both ends of a coupling. The male thread is disposed at an end of a pipe. The female thread includes buttress thread. A torque shoulder is disposed in front of the buttress thread. The female thread is connected to the torque shoulder via a tool withdrawal groove. A protruding threaded segment is disposed on any one of a fourth to seventh tooth of the female thread to prevent high pressure gas from leaking.

Abstract: A riser assembly and method of forming where the riser assembly is made up of tubular members joined together. A metal spray process applies a layer of cladding onto ends of the tubular members and the ends are threaded to form respective box and pin configurations. Grooves are provided onto the surface of the tubular members beneath where the metal spray is applied for enhancing adhesion of the cladding and tubular members. The layer of cladding provides sufficient material so that threads may be selectively formed on the outer or the inner surface of the tubular members.

Abstract: A threaded pipe connector, including: a pipe body including an external thread on one end; and a coupling including an internal thread on a corresponding end. Both the external thread and the internal thread are buttress threads capable of matching with each other. A ratio of thread height to pitch is 0.25-0.35, bearing surface angle is ?15-3°, and guide surface angle is 10-50°. A clearance is provided between a thread crest and a thread root after engagement of the external and internal threads. A sealing area between the pipe body and the coupling includes in sequence a first cylindrical transitional area, a cylindrical sealing area, a secondary cylindrical transitional area, a conical sealing area, and a conical transitional area. Tapers of both sides of the conical sealing area are the same. One end of the conical transitional area is connected with a torque shoulder.

Abstract: A threaded joint for a steel pipe includes a pin and a box each of which is provided with a contact surface that includes an unthreaded metal contact portion having a seal portion and a threaded portion. This threaded joint includes an ultraviolet ray-curable resin coating film that is formed on the contact surface of at least one of the pin and the box; and an acrylic silicone resin coating film that is formed on at least a portion of a surface of the ultraviolet ray-curable resin coating film.