A multi-walled pipe and a method for its manufacture involves a steel sheet forming a steel source layer to which a nickel source layer is applied on at least one or both sides. A solder source layer is applied to the one nickel source layer, or one of the two, or both, nickel source layers. The multi-walled pipe is formed from a strip of the coated metal sheet by rolling. The walls of the pipe are soldered by heating. In one form, the heating takes place by radiation. In another, it takes place by induction.

This disclosure relates to a method for manufacturing a double pipe, including: a primary roll forming step of forming bending portions on both sides of a strip for an external pipe in a longitudinal direction; a stacking step of stacking a strip for an internal pipe on the strip for the external pipe; a secondary roll forming step of mechanically coupling the strip for the external pipe and the strip for the internal pipe; a forming step of forming the strip for the external pipe and the strip for the internal pipe, mechanically coupled to each other, into a pipe shape; a welding step of bonding the bending portions on both sides of the strip for the external pipe, and the strip for the internal pipe, which are formed into the pipe shape; and a heat treatment step of heat-treating bonded portions of the strip.

A method of making a heat exchanger includes providing an inner tube extending longitudinally along a central axis and having an inner surface bounding a product chamber and an outer surface. An outer tube is formed and positioned about the inner tube. The outer tube is disposed coaxially about and circumscribing the inner tube in a radially spaced relationship. Forming the outer tube and positioning the outer tube about the inner tube occur simultaneously.

A pipe body, wherein the pipe body (10) has a welded portion (11) at both ends of the pipe body, aligned in a widthwise direction of the pipe body (10). The thickness of the welded portion (11) decreases gradually from the inside to the outside of the pipe, and an outer end of the welded portion (11) is located at a center portion of the pipe body (10) in a thickness direction. The configuration of the welding structure enhances the strength of the welded portion of the pipe, so that the pipe will not crack easily when it is reworked by flaring or bending, thus having high reworkability. In addition, a pipe (100) made of the pipe body (10) and a method of making the pipe (100) are disclosed.

A method for producing a multilayer large pipe having an outer support layer and at least one inner liner layer. Advantages with regard to productivity and the properties of the multilayer large pipe are achieved by the sequence of method steps wherein production of a support sheet is pre-bent to a predetermined initial bending radius for the support layer and at least one liner sheet is pre-bent to a predetermined initial bending radius for the liner layer, placement of the at least one pre-bent liner sheet against the inside of the pre-bent support sheet, with a positioning and parallel alignment of its longitudinal edges extending in the direction of the bending axis in order to form the support layer and the at least one liner layer, there is integral joining of at least one of two longitudinal edges of the at least one liner sheet to the support sheet, shaping of the composite of the integrally joined support layer and at least one liner layer to form a slit multilayer large pipe by a bending machine, with nonpositive, frictional engagement in liner regions that are not integrally joined, and there is closing of the remaining gap of the slit multilayer large pipe with a longitudinal seam by welding.

A method of manufacturing a double-walled elbow pipe segment, comprising the steps of: (a) providing an inner pipe member; (b) providing at least one first support member, and positioning said at least one first support member coaxially over said inner pipe member; (c) providing an outer pipe member and slidably positioning said assembled inner pipe member and said at least one first support member within said outer pipe member such that said at least one first support member is supportingly engaged with an outer surface of said inner pipe member and an inner surface of said outer pipe member, and (d) bending a pipe assembly of said inner pipe member, said at least one first support member and said outer pipe member into at least one first elbow section of a predetermined first angle and in a predetermined first direction between an upstream end portion and a downstream end portion of said pipe assembly.

Method for manufacturing a tube of metal in which sensors are attached to tubes, which register and signal a damage of the tube. It is detrimental that protection of the sensors at these tubes against environmental influences is complex. In contrast, it is an object of the present disclosure to provide a method for manufacturing a tube, in which the signal line can be protectively mounted. To solve this object, a method for manufacturing a tube of metal is suggested with an outer tube and an inner tube, wherein a groove is drawn in an inner surface of the outer tube or in an outer surface of the inner tube and subsequently the inner tube and the outer tube are drawn together through a drawing die, wherein the inner dimension of the outer tube is reduced such that after the drawing the outer tube is force-fitted onto the inner tube.

A method of making an annular component includes forming sheet feedstock into an annular shape disposed about a central axis; and bonding one portion of the feedstock to another portion of the feedstock using ultrasonic welding, so as to fix the annular shape.

A heat exchanger having at least one inner conduit comprising of a second tubular member coaxially disposed within a first tubular member, wherein the second tubular member outer surface is in contact with the first tubular member inner surface. Each of the first and second tubular members is composed of a material with an approximately 0.015 inch maximum wall thickness.

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.