The present invention discloses an inner pipe for a liquid heating apparatus, including a hollow pipe body made of a metal or an alloy, where a pipe wall thickness of the pipe body is 0.3-1.0 mm; through a machining method of rolling or pressing, a spiral diversion structure is machined on an inner peripheral wall of the pipe body along an axial direction of the pipe body, so that the spiral division structure is formed to extend along the axial direction of the pipe body. The present invention further discloses a liquid heating apparatus and a manufacturing method therefor. The liquid heating apparatus includes the inner pipe and the outer pipe; a heating assembly is disposed on the outer peripheral wall of the outer pipe.

A ball screw device includes a nut (3), a screw shaft, and a plurality of balls arranged between the nut (3) and the screw shaft. The nut (3) includes a first member (11) disposed to surround the screw shaft, a second member (10) disposed between the screw shaft and the first member (11), and a third member (12) disposed between the first member (11) and the second member (10). The third member (12) includes a laminate body (12A) having a plurality of plates (22a, 22b) laminated in an axial direction. The laminate body (12A) includes an inner surface facing an outer surface of the second member (10). The inner surface of the laminate body (12A) has a shape corresponding to a shape of the outer surface of the second member (10).

Machine for forming, by means of a pressurized fluid, and for profiling, by means of profiling tools, a metal tubular product, for instance a pipe, in one and the same work cycle, in particular for forming a tubular product in two different portions thereof by using one injector only and forming the tubular product in two different non-adjacent portions by using two injectors.

A metal bellows for downhole use includes: a bellows capsule with a first end and a second end; an inner diameter side and an outer diameter side arranged between the first end and the second end; where the bellows capsule comprises a first bellows convolution and second bellows convolution and optionally additional bellows convolutions; and each bellows convolution comprises: a root on the inner diameter side of the bellows capsule; a first sidewall extending from the root toward the outer diameter side of the bellows capsule with a first connection point at the distal end; a second sidewall extending from the root toward the outer diameter side of the bellows capsule with a second connection point at the distal end and wherein the second sidewall is on the opposite side of the root as the first sidewall; wherein: the bellows convolutions are formed as a single piece; and the second sidewall connection point of the first bellows convolution is permanently affixed to the first sidewall connection point of the second bellows convolution.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.

A method is disclosed for pressure forming a metal preform including shock annealing of the preform and subsequently preheating the preform prior to pressure forming. Shock annealing may be carried out as differential shock annealing in which different regions of the preform are annealed to different degrees. Preheating may be carried out by differentially preheating, optionally shock preheating, different regions of the preform for preheating at least those regions of the preform which will be subject to elevated expansion during pressure forming. Shock annealing by induction heating can lower energy consumption, reduce processing times and allow for larger expansion of the preform.

Bellows are devices used to compensate linear, thermal, or angular movement/expansion. In oil and gas industry bellows are used in gas lift valves as a slidable seal between two gases. Gas lift valves are used in process of oil artificial lift from wells. Bellows having very thin walls are not well suited for pressures higher than approximately 200 PSI. To withstand much higher pressures bellows are being crimped, process that compresses the bellow to shorter length which increases bellow mechanical toughness. This patent application refers to bellow crimping method that uses initially balanced internal and external pressure to crimp bellow to desired length and maintain perfect bellow elements-convolution geometry using custom designed crimping device.

A method for forming a conduit with a radial flange for forming part of a beaded coupling by: positioning a conduit blank in a forming die, wherein the forming die defines a radially extending recess; inserting a forming post in the conduit blank to define an annular space therebetween; inserting a flexible material in the annular space between the post and the conduit; placing a sleeve in a bearing relationship with the flexible material; compressing the flexible material between the post and the sleeve to force the flexible material against the conduit to expand the conduit outward into engagement with the radially extending recess in the forming die to form an annular flange; and releasing compression on the flexible material.

A machine for forming, using a pressurized fluid, and for profiling, using profiling tools, a metal tubular product, for instance a pipe, in one and the same work cycle. In particular a machine for forming a tubular product in two different portions thereof by using one injector only and forming the tubular product in two different non-adjacent portions by using two injectors.

A machine for forming, using a pressurized fluid, and for profiling, using profiling tools, a metal tubular product, for instance a pipe, in one and the same work cycle. In particular a machine for forming a tubular product in two different portions thereof by using one injector only and forming the tubular product in two different non-adjacent portions by using two injectors.