The present disclosure relates to a tube structure comprising an inner tube of metal and an outer tube of metal, wherein the inner tube extends in the outer tube, and wherein either the inner tube and the outer tube are mechanically tight fitted over the entire length of the inner tube, at least one space in a radial direction of the tube structure in the form of a groove extends at least in an outer surface of the inner tube or in an inner surface of the outer tube, and the at least one space extends in a longitudinal direction of the inner tube and over an entire longitudinal extension of the inner tube, or a spacer tube is located between the inner tube and the outer tube, the inner tube, the outer tube and the spacer tube are mechanically tight fitted over the entire length of the spacer tube, the spacer tube comprises at least one space in the form a slit extending in a radial direction of the tube structure from an outer surface of the inner tube to an inner surface of the outer tube, the at least one space extends in a longitudinal direction of the spacer tube and over an entire longitudinal extension of the spacer tube, and wherein the at least one space is at least partially filled with a thermal interface material providing a thermal contact between the outer tube and the inner tube.

A method for producing capillaries from nonferrous alloys, in particular of Al, which includes the continuous cold rotary extrusion of a blank having a solid cross-section, obtained by casting, in order to produce a tube having a hollow cross-section. The deformation of the blank to be extruded is achieved only by using friction force. The method further includes at least one step of cold drawing of the extruded tube in order to reduce its diameter to the diameters corresponding to a capillary.

A method for producing capillaries from nonferrous alloys, in particular of Al, which includes the continuous cold rotary extrusion of a blank having a solid cross-section, obtained by casting, in order to produce a tube having a hollow cross-section. The deformation of the blank to be extruded is achieved only by using friction force. The method further includes at least one step of cold drawing of the extruded tube in order to reduce its diameter to the diameters corresponding to a capillary.

A method of making a medical guidewire including providing a wire having a length that includes a proximal length and a distal length. The method further includes applying cold work to the distal length and not applying cold work to the proximal length, thereby imparting to the distal length a diameter that is smaller than the proximal length diameter; and applying a reducing process to the wire whereby the proximal length is reduced to have an outer diameter that is the same as the outer diameter of the distal length. The proximal length has an inner diameter and the distal length has an inner diameter that is less than the inner diameter of the proximal length.

A method of producing a clad billet includes inserting a solid carbon or low-alloy steel (CS) material into a hollow interior of the slightly larger diameter (CRA) cylinder so that a standoff gap is provided between an outer surface of the (CS) material and the inner diameter of the (CRA) cylinder; providing an explosive material around the (CRA) cylinder; detonating the explosive material to collapse at least the inner diameter of the corrosion resistant alloy cylinder onto the outer surface of the solid carbon or low-alloy steel material and eliminate the standoff gap, creating at least a partial metallurgical bond at an interface with the outer surface and resulting in a composite billet assembly, and extruding the composite billet assembly to reduce its size and form the clad billet having a metallurgical bond between the (CS) material and the (CRA) cylinder.

A method in accordance with the present application includes sending a raw tube from a drum to an unwinding side capstan while the raw tube is rotated around a central axis perpendicular to a winding shaft of the drum by rotating the drum and the unwinding side capstan about the central axis concurrently with unwinding of the raw tube from the drum holding the raw tube, on an inner surface of which multiple straight grooves along a longitudinal direction of the raw tube are formed with an interval in a circumferential direction, in a coil shape, to wind the raw tube around the unwinding side capstan, and drawing in which the unwound raw tube is drawn while the diameter of the raw tube is reduced, and then the raw tube is wound around the drawing side capstan to twist the raw tube and obtain an inner spiral grooved tube.

A method in accordance with the present application includes sending a raw tube from a drum to an unwinding side capstan while the raw tube is rotated around a central axis perpendicular to a winding shaft of the drum by rotating the drum and the unwinding side capstan about the central axis concurrently with unwinding of the raw tube from the drum holding the raw tube, on an inner surface of which multiple straight grooves along a longitudinal direction of the raw tube are formed with an interval in a circumferential direction, in a coil shape, to wind the raw tube around the unwinding side capstan, and drawing in which the unwound raw tube is drawn while the diameter of the raw tube is reduced, and then the raw tube is wound around the drawing side capstan to twist the raw tube and obtain an inner spiral grooved tube.

The present disclosure relates to a tube structure comprising an inner tube of metal and an outer tube of metal, wherein the inner tube extends in the outer tube, and wherein either the inner tube and the outer tube are mechanically tight fitted over the entire length of the inner tube, at least one space in a radial direction of the tube structure in the form of a groove extends at least in an outer surface of the inner tube or in an inner surface of the outer tube, and the at least one space extends in a longitudinal direction of the inner tube and over an entire longitudinal extension of the inner tube, or a spacer tube is located between the inner tube and the outer tube, the inner tube, the outer tube and the spacer tube are mechanically tight fitted over the entire length of the spacer tube, the spacer tube comprises at least one space in the form a slit extending in a radial direction of the tube structure from an outer surface of the inner tube to an inner surface of the outer tube, the at least one space extends in a longitudinal direction of the spacer tube and over an entire longitudinal extension of the spacer tube, and wherein the at least one space is at least partially filled with a thermal interface material providing a thermal contact between the outer tube and the inner tube.

The present invention relates to an absorption chiller which comprises an evaporator, an absorber, a regenerator and a condenser and has an absorbing solution and a refrigerant circulating. A heat transfer pipe, which is provided on one or more of the evaporator, absorber, regenerator and condenser, is comprised, and a ductile stainless steel pipe, which has 1% or less of delta ferrite matrix structure on the basis of the grain size area, is applied to the heat-transfer pipe. Therefore, copper-level flexibility can be obtained in comparison with an existing stainless steel pipe.

A method of manufacturing a two-layer metal wire, in particular in a gold-based alloy and of silver, which comprises a succession of steps which consist in coupling an outer metal tube (2) to an inner metal tube (4) interposing a first binding thickness (3) in low-melting metal material, welding the inner surface (12) of the outer metal tube (2) to the outer surface (13) of the first binding thickness (3) and the inner surface (13″) of the same first binding thickness (3) to the outer surface (141) of the inner metal tube (4), to firmly associate the outer tube (2) with the inner tube (4) together, so as to form a tubular element (7, 107) which has at least three metal layers, and then draw, by final drawing, the tubular element (7, 107) to obtain a compound metal wire (9) from at least three metal layers. The object of the present invention is also a semi-finished tubular element (7, 107), having at least three metal layers, which comprises an outer metal tube (2), an Inner metal tube (4) and a first binding thickness (3) interposed between the outer metal tube (2) and the inner metal tube (4).