An example fitting includes: a fitting body having counterbore, where the counterbore defines an annular shoulder within tire fitting body: a spring having a first end interfacing with the annular shoulder of the counterbore; and a seal carrier having: (i) a first end face interfacing with a second end of the spring, (ii) a second end face configured to interface with an internal surface of a port, such that the spring is configured to apply a biasing force on the seal carrier toward the internal surface of the port, (iii) a first annular groove on an exterior peripheral surface of the seal carrier, where the first annular groove is configured to have a radial seal disposed therein, and (iv) a second annular groove in the second end face, where the second annular groove is configured to have a face seal disposed therein.

A screw joint in which an efficient screw length of a joint portion is achieved. This screw joint is for an oil well pipe of an integral type and includes: (i) a pin that is provided with a male screw portion which is a male taper screw, at one end of a steel pipe; and (ii) a box that is provided with a female screw portion which is a female taper screw fitted to the male screw portion, at one end of the steel pipe, in which a structure, in which the pin and the box are in metal contact with each other to seal a fluid, is provided at least at one place of a seal portion on an outer peripheral surface side of a pipe end side of the pin and a seal portion on an inner peripheral surface side of a pipe end side of the box.

A threaded connection for steel pipe that provides high torque performance, high tension performance and high sealability is provided. A threaded connection 1 includes: a tubular pin 10 including a pin shoulder 12, a male thread 11 and a pin seal 13; and a tubular box 20 including a box shoulder 22, a female thread 21 and a box seal 23. The male and female threads 11 and 21 are constituted by wedge threads. The pin seal 13 is provided between the pin shoulder 12 and the male thread 11. The box seal 23 corresponds to the pin seal 13 and is located on the inner peripheral surface of the box 20. When the connection is made up, the pin shoulder 12 is spaced apart from the box shoulder 22. The threaded connection 1 satisfies the following expression, (1):
3%≤(LP−SP)/LP≤7%  (1). In expression (1), LP is the pitch between loading flanks 111 of the male thread 11, and SP is the pitch between stabbing flanks 112 of the male thread 11.

A threaded connection for steel pipe that provides high torque performance, high tension performance and high sealability is provided. A threaded connection 1 includes: a tubular pin 10 including a pin shoulder 12, a male thread 11 and a pin seal 13; and a tubular box 20 including a box shoulder 22, a female thread 21 and a box seal 23. The male and female threads 11 and 21 are constituted by wedge threads. The pin seal 13 is provided between the pin shoulder 12 and the male thread 11. The box seal 23 corresponds to the pin seal 13 and is located on the inner peripheral surface of the box 20. When the connection is made up, the pin shoulder 12 is spaced apart from the box shoulder 22. The threaded connection 1 satisfies the following expression, (1):
3%≤(LP−SP)/LP≤7%  (1). In expression (1), LP is the pitch between loading flanks 111 of the male thread 11, and SP is the pitch between stabbing flanks 112 of the male thread 11.

A threaded connection for pipes according to the present embodiment includes a pin, a box, and a Zn—Ni alloy plating layer. The pin has a pin contact surface that includes an external thread part. The box has a box contact surface that includes an internal thread part. The Zn—Ni alloy plating layer is disposed on or above at least one of the pin contact surface and the box contact surface. The Zn—Ni alloy plating layer contains graphite.

An improved coupling for joining pipes of characteristics in accordance with API standards provides for the extraction of crude oils from oil wells, whose improved characteristics, according to the new procedure, achieve a hermetic design of the coupling and, more specifically, relate to the improvement of the threading in the joints by means of modern systems for the fabrication thereof in both the pipe terminals of the well and in the joining of the rounded threads, with computerised rnanufactuting systems and with the incorporation of a shoulder located interiorly in the coupling to achieve, first, the elimination of free spaces that might cause turbulence within the coupling, and second, to create a hermetic metal-to-metal closure and additionally a flexible hydrogenated nitrogen seal, located behind the shoulder, ensuring the hermetic nature of the joint.

An improved coupling for joining pipes of characteristics in accordance with API standards provides for the extraction of crude oils from oil wells, whose improved characteristics, according to the new procedure, achieve a hermetic design of the coupling and, more specifically, relate to the improvement of the threading in the joints by means of modern systems for the fabrication thereof in both the pipe terminals of the well and in the joining of the rounded threads, with computerised rnanufactuting systems and with the incorporation of a shoulder located interiorly in the coupling to achieve, first, the elimination of free spaces that might cause turbulence within the coupling, and second, to create a hermetic metal-to-metal closure and additionally a flexible hydrogenated nitrogen seal, located behind the shoulder, ensuring the hermetic nature of the joint.

A sealing device is provided for use with a fitting. The fitting has circular port and a flow path with a longitudinal axis. A circular port encircles a portion of the flow path opposite the port with the sealing device inserted into the port. The sealing device has a circular top with two opposing surfaces depending therefrom but inclined so the surfaces are closer at the top. A continuous sidewall joins the periphery of the two surfaces. The opposing surfaces are inclined and spaced apart further at the top than at an end opposite the top. A cylindrical hole through the opposing surfaces encircles the flow path during use.

A sealing device is provided for use with a fitting. The fitting has circular port and a flow path with a longitudinal axis. A circular port encircles a portion of the flow path opposite the port with the sealing device inserted into the port. The sealing device has a circular top with two opposing surfaces depending therefrom but inclined so the surfaces are closer at the top. A continuous sidewall joins the periphery of the two surfaces. The opposing surfaces are inclined and spaced apart further at the top than at an end opposite the top. A cylindrical hole through the opposing surfaces encircles the flow path during use.

A threaded connection for pipe includes a pin and a box. The threaded connection for pipe includes a Zn—Ni alloy plated layer and a solid lubricant coating. The Zn—Ni alloy plated layer is formed on a contact surface of at least one of the pin and the box and contains 10 to 16 mass % of Ni. The solid lubricant coating is formed on the Zn—Ni alloy plated layer. The contact surface on which the Zn—Ni alloy plated layer is formed is ground. Now define arithmetic average roughness of the surface of the Zn—Ni alloy plated layer as Ra1, and arithmetic average roughness of the contact surface as Ra2. Ra1 ranges from 0.1 to 3.2 μm. Ra1 is more than Ra2.