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 tubular member for threadably engaging another tubular member to form a tubular string includes a first end including a helical female thread formed in an outer surface of the tubular member, wherein the female thread includes a slot extending radially inwards from the outer surface, and a root extending radially inwards from the slot, wherein the root has a maximum width that is greater than a maximum width of the slot, a second end opposite the first end and including a helical male thread formed on an inner surface of the tubular member, wherein the male thread includes a shank extending radially outwards from the inner surface, and a notch extending radially outwards from the shank, wherein the notch has a maximum width that is greater than a maximum width of the shank.

A threaded joint with excellent tensile strength, comprising: a pin having an externally threaded part comprising a first and second externally threaded sections across a step on an outer periphery on a distal-end side of a first steel pipe or tube; and a box having an internally threaded part comprising a first and second internally threaded sections across the step on an inner periphery on a distal-end side of a second steel pipe or tube, the externally threaded part being screwed to the internally threaded part to join the pin and the box. The threaded joint has a first and second thread sequence with lengths L1 and L2, respectively, and cross-sectional areas P1, P2, B1, and B2 at end positions 4, 5, 6, and 7, respectively, satisfying Formulas (1) and (2): (P2, B2).sub.min≤P1/{L1/(L1+L2)}(1) and (P2, B2).sub.min≤B1/{L2/(L1+L2)}(2), where (P2, B2).sub.min represents P2 or B2, whichever is smaller.

This invention provides a threaded connection for pipes or tubes having excellent misalignment resistance and high torque on shoulder resistance, and also having excellent corrosion resistance properties, as well as a method for producing the threaded connection for pipes or tubes. The threaded connection for pipes or tubes includes a pin and a box. The pin and the box include contact surfaces having threaded portions and unthreaded metal contact portions. The threaded connection for pipes or tubes includes, on at least one of the contact surfaces of the pin and the box, surface roughness, a Zn—Ni alloy plating layer, a Cu—Sn—Zn alloy plating layer and a solid lubricant coating layer. These are deposited from the contact surface side in the order of: surface roughness, the Zn—Ni alloy plating layer, the Cu—Sn—Zn alloy plating layer and the solid lubricant coating layer.

A threaded joint with excellent tensile strength, comprising: a pin having an externally threaded part comprising a first and second externally threaded sections across a step on an outer periphery on a distal-end side of a first steel pipe or tube; and a box having an internally threaded part comprising a first and second internally threaded sections across the step on an inner periphery on a distal-end side of a second steel pipe or tube, the externally threaded part being screwed to the internally threaded part to join the pin and the box. The threaded joint has a first and second thread sequence with lengths L1 and L2, respectively, and cross-sectional areas P1, P2, B1, and B2 at end positions 4, 5, 6, and 7, respectively, satisfying Formulas (1) and (2): (P2, B2).sub.min≤P1/{L1/(L1+L2)}(1) and (P2, B2).sub.min≤B1/{L2/(L1+L2)}(2), where (P2, B2).sub.min represents P2 or B2, whichever is smaller.

An oil-well metal pipe according to the present disclosure has a pipe main body including a first end portion and a second end portion. The pipe main body includes a pin formed at the first end portion, and a box formed at the second end portion. The pin includes a pin contact surface including an external thread part, and the box includes a box contact surface including an internal thread part. The oil-well metal pipe according to the present disclosure also includes a resin coating containing a resin, a solid lubricant powder, and copper phthalocyanine on or above at least one of the pin contact surface and the box contact surface.

A threaded joint (200) provides for metal-to-metal sealing on the ends of concentrically positioned inner and outer tubes when joining the concentric tubes to a single tube (107). A threaded coupling (105) secures the inner and outer tubes and joins both tubes to a single tube. The threaded connection leverages metal-to-metal sealing on the ends of each tube. The inner tube (102) may differ in length from the outer tube (101) and contains a single thread (211) at its for receiving the threaded coupling. Threading the coupling onto the inner tube establishes four flexing metal-to-metal seals (209A-D) between the threaded joint components. The inner and outer tubes maintain contact at the internal shoulder (104) as a result of preloading. If the tubes are of varying thicknesses, a nut (407) is placed between the internal shoulder and the threaded coupling to preserve contact between the tubes at the internal shoulder.

This invention provides a threaded connection for pipes or tubes having excellent misalignment resistance and high torque on shoulder resistance, and also having excellent corrosion resistance properties, as well as a method for producing the threaded connection for pipes or tubes. The threaded connection for pipes or tubes includes a pin and a box. The pin and the box include contact surfaces having threaded portions and unthreaded metal contact portions. The threaded connection for pipes or tubes includes, on at least one of the contact surfaces of the pin and the box, surface roughness, a Zn—Ni alloy plating layer, a Cu—Sn—Zn alloy plating layer and a solid lubricant coating layer. These are deposited from the contact surface side in the order of: surface roughness, the Zn—Ni alloy plating layer, the Cu—Sn—Zn alloy plating layer and the solid lubricant coating layer.

This invention provides a threaded connection for oil country tubular goods that exhibits excellent corrosion resistance and galling resistance, and a method for producing the threaded connection for oil country tubular goods. The method includes a Zn—Ni alloy plating layer formation step of forming a Zn—Ni alloy plating layer, and a chromate coating formation step of forming a chromate coating after the Zn—Ni alloy plating layer formation step. The chromate coating formation step includes a chromate treatment step and a drying step. The chromate coating formation step satisfy one or more conditions selected from the following conditions 1 to 3. Condition 1: stirring speed of the chromating solution in the chromate treatment step: a linear speed of 0.5 m/s or more; Condition 2: chromate treatment time in the chromate treatment step: less than 50 seconds; and Condition 3: drying temperature in the drying step: 60° C. or less.

A sleeve for a valve assembly has an annular body with an inside surface extending from a first axial sleeve-end to a second axial sleeve-end. The inside surface has a first cylindrical section and a second cylindrical section with a conical interior seating surface extending therebetween. A groove extends circumferentially around and radially outward in the first cylindrical section and axially away from the conical interior seating surface towards the first axial sleeve-end. The sleeve includes one or more first ports that extend radially through the first cylindrical section and spaced apart from the groove. The one or more first ports are spaced apart from the groove by a lip formed by the first cylindrical section. The lip extends continuously and entirely circumferentially around the first cylindrical surface and extends a predetermined axial distance between the groove and the one or more first ports.