A pipe joint device configured to interconnect two pipes to be inserted therein through openings of both opened ends thereof including a joint main body and a joint assembly disposed in the joint main body is provided. The joint main body includes a small-diameter part formed at a central part and large-diameter parts formed at both sides of the small-diameter part. Each of the large-diameter parts has a first horizontal part, a diameter-reduced part of which a diameter gradually decreases from the first horizontal part toward the opening, and a second horizontal part extending horizontally from the diameter-reduced part toward the opening. A portion of each of the second horizontal parts is configured as a curled part inclined toward an outer-diameter direction and the opening of the pipe joint device and then again inclined toward an inner-diameter direction and the opening and having a mountain-shaped section as a whole.

A method of incremental autofrettage is taught herein, whereby the cycle life of a metal liner in a pressure vessel is increased. This method serves to increase the yield strength of the metal liner through sequential work hardening due to repeated autofrettage at increasing pressures. By incrementally increasing the internal pressure used in the autofrettage process, the compressive stresses at an inner surface of the metal liner may be controlled so that post-pressurization buckling does not occur, yet the yield strength of the metal liner is substantially increased. The higher compressive stresses in the metal liner mean that higher Maximum Expected Operating Pressures (MEOPs) may be used without detracting from the cycle life of the metal liner, or alternatively, for lower pressures, a longer metal liner cycle life may be obtained. Either internal or external pressures may be used, generated by a pressure source, or a suitable die.

An apparatus and method for manufacturing a pipe assembly having an inner pipe and an outer jacket may include a support member, a pair of lance assemblies and a pair of caps. The support member supports the outer jacket of the pipe assembly and is drivable between a first position and a second position. The pair of lance assemblies are configured to be inserted into opposing ends of the inner pipe such that the pair of lance assemblies engage an inner wall of the inner pipe. One of the outer jacket and the inner pipes moves relative to the other of the outer jacket and the inner pipe to center the inner pipe within the outer jacket when the support member is driven from the first position to the second position. Insulation is inserted through at least one cap into a space between the inner pipe and outer jacket.

An apparatus and method for manufacturing a pipe assembly having an inner pipe and an outer jacket may include a support member, a pair of lance assemblies and a pair of caps. The support member supports the outer jacket of the pipe assembly and is drivable between a first position and a second position. The pair of lance assemblies are configured to be inserted into opposing ends of the inner pipe such that the pair of lance assemblies engage an inner wall of the inner pipe. One of the outer jacket and the inner pipes moves relative to the other of the outer jacket and the inner pipe to center the inner pipe within the outer jacket when the support member is driven from the first position to the second position. Insulation is inserted through at least one cap into a space between the inner pipe and outer jacket.

A manufacturing process is provided that includes arranging a tubular body with a mandrel. The tubular body circumscribes an outer surface of the mandrel and includes a panel and a sheet. The panel includes a porous first skin, a second skin and a cellular core between and connected to the porous first skin and the second skin. The sheet is configured with the second skin to form a pressure vessel. The first skin and the cellular core are located within the pressure vessel. At least a portion of the outer surface comprises an axially convex geometry. The panel is heated. The heated panel is shaped to at least partially conform to the outer surface by pressurizing fluid within the pressure vessel.

Aspects of the disclosure are directed to a bonding of a first skin and a second skin to a core material, coupling a sheet to the first skin to form with the first skin an enclosure containing the second skin and the core material, exposing the first skin, the second skin, and the core material to heat, and based on the exposition of heat, applying pressure via the enclosure to the first skin to cause the first skin to deform and expand to a shape of a die.

Aspects of the disclosure are directed to a bonding of a first skin and a second skin to a core material, coupling a sheet to the first skin to form with the first skin an enclosure containing the second skin and the core material, exposing the first skin, the second skin, and the core material to heat, and based on the exposition of heat, applying pressure via the enclosure to the first skin to cause the first skin to deform and expand to a shape of a die.

A composite pipe includes a carrier pipe and at least one protective pipe. The carrier pipe is produced from a non-corrosion resistant steel, which has at least a partially austenitic structure, with the following chemical composition (in wt. %): C: 0.005 to 1.4; Mn: 5 to 35; the remainder being iron including unavoidable elements accompanying steel, with the optional alloying of the following elements (in wt. %): Ni: 0 to 6; Cr: 0 to 9; Al: 0 to 15; Si: 0 to 8; Mo: 0 to 3; Cu: 0 to 4; V: 0 to 2; Nb: 0 to 2; Ti: 0 to 2; Sb: 0 to 0.5; B: 0 to 0.5; Co: 0 to 5; W: 0 to 3; Zr: 0 to 4; Ca: 0 to 0.1; P: to 0.6; S: 0 to 0.2; N: 0.002 to 0.3. In a method for producing a composite pipe of this type, the carrier pipe and the at least one protective pipe are mechanically or metallurgically connected to one another.

A composite pipe includes a carrier pipe and at least one protective pipe. The carrier pipe is produced from a non-corrosion resistant steel, which has at least a partially austenitic structure, with the following chemical composition (in wt. %): C: 0.005 to 1.4; Mn: 5 to 35; the remainder being iron including unavoidable elements accompanying steel, with the optional alloying of the following elements (in wt. %): Ni: 0 to 6; Cr: 0 to 9; Al: 0 to 15; Si: 0 to 8; Mo: 0 to 3; Cu: 0 to 4; V: 0 to 2; Nb: 0 to 2; Ti: 0 to 2; Sb: 0 to 0.5; B: 0 to 0.5; Co: 0 to 5; W: 0 to 3; Zr: 0 to 4; Ca: 0 to 0.1; P: to 0.6; S: 0 to 0.2; N: 0.002 to 0.3. In a method for producing a composite pipe of this type, the carrier pipe and the at least one protective pipe are mechanically or metallurgically connected to one another.

A pipe joint device configured to interconnect two pipes to be inserted therein through openings of both opened ends thereof including a joint main body and a joint assembly disposed in the joint main body is provided. The joint main body includes a small-diameter part formed at a central part and large-diameter parts formed at both sides of the small-diameter part. Each of the large-diameter parts has a first horizontal part, a diameter-reduced part of which a diameter gradually decreases from the first horizontal part toward the opening, and a second horizontal part extending horizontally from the diameter-reduced part toward the opening. A portion of each of the second horizontal parts is configured as a curled part inclined toward an outer-diameter direction and the opening of the pipe joint device and then again inclined toward an inner-diameter direction and the opening and having a mountain-shaped section as a whole.