A threaded connection for steel pipes is provided that exhibits improved sealability against the external pressure while maintaining the sealability against the internal pressure. A threaded connection for steel pipes includes a pin and a box. The pin includes a nose, a tapered inner male thread, a tapered outer male thread, a pin inner sealing surface, a pin intermediate shoulder surface, a pin intermediate sealing surface, and a pin annular portion. The box includes a recess corresponding to the nose, a tapered inner female thread, a tapered outer female thread, a box inner sealing surface, a box intermediate shoulder surface, a box intermediate sealing surface, and a box annular portion. The threaded connection satisfies expressions (1) and (2), provided below. α1 is a taper slope of the inner male thread, and α2 is a taper slope of the outer male thread. $\begin{array}{cc}\alpha 1>\mathrm{\alpha 2},\mathrm{and}& \left(1\right)\\ 0.5\leqq \frac{L1\mathrm{\alpha 1}}{L2\mathrm{\alpha 2}}\leqq 1.2& \left(2\right)\end{array}$ In expression (2), L1 is a distance between the tip of the pin and the pin intermediate shoulder surface as measured along the pipe-axis direction when the pin and box have not been made up, and L2 is a distance between the box intermediate shoulder surface and the tip of the box as measured along the pipe-axis direction when the pin and box have not been made up.

The threaded connection for pipes includes a pin, a box and a Zn—Ni alloy plating layer. The pin has a pin-side contact surface that includes a pin-side thread part. The box has a box-side contact surface that includes a box-side thread part. The Zn—Ni alloy plating layer is formed on at least one of the pin-side contact surface and the box-side contact surface. The Zn—Ni alloy plating layer is consisting of Zn, Ni, trace amount of Cr and impurities. The trace amount of Cr content of the Zn—Ni alloy plating layer is 5.0×10 counts/sec or more in terms of Cr intensity as measured by secondary ion mass spectrometry using O.sub.2.sup.+ ions as bombarding ions.

The threaded connection for pipes includes a pin, a box and a Zn—Ni alloy plating layer. The pin has a pin-side contact surface that includes a pin-side thread part. The box has a box-side contact surface that includes a box-side thread part. The Zn—Ni alloy plating layer is formed on at least one of the pin-side contact surface and the box-side contact surface. The Zn—Ni alloy plating layer is consisting of Zn, Ni, trace amount of Cr and impurities. The trace amount of Cr content of the Zn—Ni alloy plating layer is 5.0×10 counts/sec or more in terms of Cr intensity as measured by secondary ion mass spectrometry using O.sub.2.sup.+ ions as bombarding ions.

A valve connector includes a connecting member, a threaded member, a joint member, and first and second connection assemblies. The connecting member is inserted into an axial hole of the threaded member to cause an abutting portion of the connecting member to enter into the axial hole. The joint member forms two threaded sections at two opposite ends thereof. The two threaded sections are alternatively detachably connected to a threaded portion of the threaded member so that a first seal ring of the first connection assembly and a second seal ring of the second connection assembly are alternatively removably abutted against the abutting portion for connecting a Schrader valve and a Presta valve.

A valve connector includes a connecting member, a threaded member, a joint member, and first and second connection assemblies. The connecting member is inserted into an axial hole of the threaded member to cause an abutting portion of the connecting member to enter into the axial hole. The joint member forms two threaded sections at two opposite ends thereof. The two threaded sections are alternatively detachably connected to a threaded portion of the threaded member so that a first seal ring of the first connection assembly and a second seal ring of the second connection assembly are alternatively removably abutted against the abutting portion for connecting a Schrader valve and a Presta valve.

The disclosure relates to a connector that includes at least a female port, wherein the female port is configured for receiving, in a gas tight manner, alternatively, two male connectors of two different given types. The two male connectors can have the same thread pitch and diameter. The female port can include a female thread suitable for respectively receiving threads of the two male connectors. The female port can include two first parts of two different sealing devices, one having a seal and the other being metal-on-metal, each compatible with one of the male connectors, and each of a given type different to the other.

The disclosure relates to a connector that includes at least a female port, wherein the female port is configured for receiving, in a gas tight manner, alternatively, two male connectors of two different given types. The two male connectors can have the same thread pitch and diameter. The female port can include a female thread suitable for respectively receiving threads of the two male connectors. The female port can include two first parts of two different sealing devices, one having a seal and the other being metal-on-metal, each compatible with one of the male connectors, and each of a given type different to the other.

A curative free sealant composition for sealing joints between male and female parts, the sealant composition comprising a solid resin component, a solid (meth)acrylate polyurethane component, and an ethoxylated bisphenol-A (meth)acrylate component.

A curative free sealant composition for sealing joints between male and female parts, the sealant composition comprising a solid resin component, a solid (meth)acrylate polyurethane component, and an ethoxylated bisphenol-A (meth)acrylate component.

The composition according to the present disclosure is a composition for forming a lubricant coating layer on or above a threaded connection for pipes, and contains polyisobutylene, a metal soap, a wax and a basic metal salt of an aromatic organic acid. The threaded connection for pipes according to the present disclosure includes: a pin having a pin-side contact surface which includes a pin-side threaded portion; a box having a box-side contact surface which includes a box-side threaded portion; and a lubricant coating layer formed from the aforementioned composition as an outermost layer on or above at least one of the pin-side contact surface and the box-side contact surface.