A drill pipe comprises a drill pipe body and a tool joint that comprises a rotary shoulder connection is disclosed. The rotary shoulder connection comprises: a box connection, wherein the box connection has a box outer adius, a box counter bore radius and a box inner radius, and box threads having a box thread form cut along a box taper: a pin connection, wherein the pin connection has a pin outer radius, a pin cylinder radius and a pin nose radius, and pin threads having a pin thread form cut along a pin taper to align with the box threads inside the box connection; and a primary shoulder connection comprising: a primary box shoulder that is angled or curved; and a primary pin shoulder that is angled or curved. Methods of using the drill pipe are also disclosed.

A threaded connection for a steel pipe includes a box which is an opening end of a second pipe and a truncated cone shaped pin which is an end of a first pipe and is inserted into the box, wherein the pin includes a male thread portion which is a tapered thread and a seal portion which includes a tapered surface, the box includes a female thread portion which is a tapered thread and a seal portion which includes a tapered surface, and in a state before make-up between the pin and the box, a minimum diameter of the tapered surface of the pin is smaller than a maximum diameter of the tapered surface of the box.

A threaded connection for steel pipe with improved sealing performance is provided. A threaded connection (1) includes a pin (10) and a box (20). The pin (10) includes a pin shoulder surface (11), a pin sealing surface (12) and a male thread (13). The box (20) includes a box shoulder surface (21), a box sealing surface (22) and a female thread (23). The male thread (13) and female thread (23) are constituted by wedge threads. When the connection has been made up, the pin shoulder surface (11) is in contact with the box shoulder surface (21), the stabbing flank and load flank of the male thread (13) are in contact with the stabbing flank and load flank, respectively, of the female thread (23), and the pin sealing surface (12) is in contact with the box sealing surface (22). The shoulder angle is 4° or larger. The shoulder angle is the angle formed by each of the shoulder surfaces (11, 21) with a plane perpendicular to the pipe axis (CL) when the connection is not made up.

In a threaded connection for pipe with a two-step thread construction, including intermediate shoulders, during stabbing, the internal-pressure sealing surface of the pin near its tip is prevented from contacting the intermediate shoulder of the box and thus receiving damage. L.sub.P, L.sub.B, h.sub.P and h.sub.B shown in FIG. 2 satisfy Expressions (1) and (2), provided below. θ.sub.seal is the angle of slope of the straight line connecting the two ends, as determined along the axial direction, of the internal-pressure sealing surface of the pin. Expression (3), provided below, is also satisfied.

L.sub.P<L.sub.B  (1)

h.sub.B<h.sub.P(L.sub.B−L.sub.P)×tan θ.sub.seal  (2)

L.sub.SP<L.sub.B−L.sub.P  (3)

A high-torque threaded connection with male and female threadforms constituted by wedge threads is provided with high shear resistance and high torque resistance. The radius of curvature r1 of the base of the load flank of the first thread 111, located at the end of the male threadform 11 associated with the tip, is not lower than the thread height Th×0.14, and more preferably not lower than Th×0.16, to improve the shear resistance of the first thread 111. Further, the thread pitch may be reduced to increase the number of threads to increase the area of contact for load flanks, or only the radius of curvature of the base of the load flank of the first thread located at the end of the male threadform associated with the tip may be increased and smaller radii of curvature may be provided for the other portions to increase the area of contact for load flanks, thereby maintaining high torque resistance.

A sealing assembly for a downhole device has first (12) and second sealing (22) components which are urged together to make up the assembly such that a first sealing surface (34) on the first component radially presses a lip member (44) on the second component to change the angle of a second sealing surface (45) in the connected assembly. The components are urged together by a driving member (60) which can have screw threads that cooperate with the first component. The lip may be annular and may be formed by an undercut or recess (42) radially inwardly or outwardly of the lip member, allowing the lip member to bend radially inwards into the recess, during insertion of the second sealing component into the first.

A hot water storage device having a vessel includes a first section formed from a moulded material and a second section formed from a moulded material. An open end of the first section is sealingly engaged with an opposing open end of the second section to form the vessel. The first and second sections each have a generally cylindrical body portion and a closed end, comprising a head portion. The vessel includes a water inlet aperture moulded into the first or second section and a water outlet aperture moulded into the first or second section and wherein the inlet and outlet apertures are located on the body portion proximal to a tangent line between the body portion and the head portion.

In a pipe joint where two pipe sections (14, 16) have threadably engaged end potions (17, 18), joint ends (32, 34) are substantially sealed to each other by a sealing surface (40, 50) on one pipe section that substantially abuts a sealing surface (42, 52) on the other pipe section. In one joint, a ring-shaped cutout(121, FIG. 7) is formed in a first pipe section and a ring-shaped spacer (120) is located in the cutout. The spacer is chosen from several that have slightly different lengths so the spacer ends contacts the corresponding sealing surface(130).

A leak-resistant pipe connection has an annular seal bulge on a pin end of the connection and a tapered seal area adjacent a secondary box shoulder of a box end of the connection. The annular seal bulge is coined on contact with the tapered seal area on initial make-up of the connection which provides a metal-to-metal seal that is very resistant to high-pressure fluid leakage even after the connection is subjected to extreme shear and tensile stresses.

High-strength, fatigue-resistant pipe connectors suitable for use in offshore risers, tendons and pipelines, such as may be connected to floating production systems (FPSs) principally used in the production of oil and gas. The present connectors include tubular pin and box components with mating frusto-conical, concentrically-grooved mating surfaces which threadingly interlock, and non-threaded (e.g., flat) mating surfaces that seal and preload (e.g., preload at least a portion of each component in compression), via axial advancement of the pin component into the box component. In such connectors, axial movement of the pin into the mating box results the in radial expansion of the box and radial contraction of the pin until the concentric thread patterns match and interlockingly snap into the connected position.