A leak-proof tube fitting assembly structure includes a liquid tube, a liquid tube fitting, and a nut for locking and connecting the liquid tube and the liquid tube fitting. The liquid tube fitting has a first connecting end, a first threaded connecting portion and a second connecting end that are axially arranged in sequence in a forward direction. The first threaded connecting portion has a first external thread. Thereby, the sealing performance of the connection of the liquid tube and the liquid tube fitting is improved to prevent leakage.

A leak-proof tube fitting assembly structure includes a liquid tube, a liquid tube fitting, and a nut for locking and connecting the liquid tube and the liquid tube fitting. The liquid tube fitting has a first connecting end, a first threaded connecting portion and a second connecting end that are axially arranged in sequence in a forward direction. The first threaded connecting portion has a first external thread. Thereby, the sealing performance of the connection of the liquid tube and the liquid tube fitting is improved to prevent leakage.

A gas-tight sealing device (10) encloses at least one part of a coupling element (12) as well as at least one section of a line element (14) connected to the coupling element (12). The the gas-tight sealing device (10) comprises a sealing device portion or wall (11) that adjoins a first sealing point and a second sealing point (16, 18). The sealing device portion or wall (11) extends around, in a gas-tight manner, the line element (14) and the coupling element (12) or a wall (20), or a further line element, in or at which the coupling element (12). The gas-tight sealing device (10) encloses a volume defined by the geometry of the sealing device portion (11) in a gas-tight manner between the first sealing point (16) and the second sealing point (16, 18).

A joint is connected to a tube and includes a joint body, nut, and ring. The joint body has a tube coupling part and a main body thread part. The nut has a nut thread part and a constricted diameter part. The ring is arranged in a space radially inward of the nut thread part. The ring abuts an abutted part of the nut. The ring has a Young's modulus greater than the tube. The ring has a curved surface part at least at a radially inward portion of the ring axially on the joint body side, the curved surface part bulging radially inward of the ring and axially toward the joint body side. A maximum thickness of the ring in a radial direction is defined as 2r, an axial length of the curved surface part of the ring is defined as h, and α=h/r being 0.5 to 1.2.

A resin tube fitting has a body with a sleeve allowing the longitudinal end of the tube to be put therein, an inner ring with a press-in portion configured to be pressed in the longitudinal end of the tube, and a union nut with a connector configured to be screwed to an outer periphery of the body to allow the longitudinal end of the tube to be put radially between the connector and the press-in portion. The inner ring and the union nut are made of resin, which has a property of contracting in response to change in ambient temperature. The radial contraction rate of the connector is higher by 0.05% or more than that of the press-in portion of the inner ring.

A hydraulic component system has a hydraulic line, a hydraulic component produced by a generative method, an annular sealing means, and a hollow fastening element. The sealing means has opposing end regions. The fastening element has an engagement region with an internally arranged circumferential surface having second engagement means and has an opposite clamping region having a second axial contact surface facing the engagement region, and is designed to surround the hydraulic line and the sealing means, and to bring about a surface contact between the first and the second axial contact surface. The receiving section, the sealing means, and the fastening element correspond to one another such that the first end region of the sealing means is pressed into the conically tapering region of the opening of the receiving section and the hydraulic line by engagement of the first and second engagement means.

A resin tube fitting has a body with a sleeve allowing the longitudinal end of the tube to be put therein, an inner ring with a press-in portion configured to be pressed in the longitudinal end of the tube, and a union nut with a connector configured to be screwed to an outer periphery of the body to allow the longitudinal end of the tube to be put radially between the connector and the press-in portion. The inner ring and the union nut are made of resin, which has a property of contracting in response to change in ambient temperature. The radial contraction rate of the connector is higher by 0.05% or more than that of the press-in portion of the inner ring.

A fitting for a tube or pipe capable of functioning a high pressures having a first fitting component adapted to receive the conduit end; a conduit gripping device such as a ferrule or ferrules and a second fitting component that can be joined to the first fitting component to cause the conduit gripping device to grip the conduit and seal when assembled. In one aspect of the invention, the first fitting component is constructed from a material that is softer than the material used to construct the second fitting component. An additional aspect of the invention include a retaining portion on the second fitting component that constrains the tube gripping device against pressure. The retaining portion can also be configured to retain the tube gripping device to the second fitting component prior to installation and in a finger-tight condition. A further aspect of the invention includes a first fitting component in which an exterior portion of the component is work hardened radially outward from the tube gripping device. The fitting may optionally be provided with a structure to effect the pull-up by torque functionality.

A pipe joint assembly including a first pipe element, a second pipe element, a pair of segments, each segment defining a first end and a second end, each first end comprising a tongue and each second end comprising a groove, each groove defining a groove shoulder surface, the tongue of the one segment defining a tongue outer surface, the tongue outer surface of the tongue of the one segment angled at a non-zero angle relative to the groove shoulder surface in an assembled and untightened position, the tongue outer surface of the tongue positioned parallel and flush to the groove shoulder surface of the groove of the second segment in an assembled and tightened condition; and a pair of fasteners configured to deflect each segment around the first pipe element and the second pipe element in the assembled and tightened condition.

A pipe joint assembly including a first pipe element, a second pipe element, a pair of segments, each segment defining a first end and a second end, each first end comprising a tongue and each second end comprising a groove, each groove defining a groove shoulder surface, the tongue of the one segment defining a tongue outer surface, the tongue outer surface of the tongue of the one segment angled at a non-zero angle relative to the groove shoulder surface in an assembled and untightened position, the tongue outer surface of the tongue positioned parallel and flush to the groove shoulder surface of the groove of the second segment in an assembled and tightened condition; and a pair of fasteners configured to deflect each segment around the first pipe element and the second pipe element in the assembled and tightened condition.