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 welding two or more conduits includes aligning end portions thereof in an abutting relationship to define a gap. The method includes performing a spatter free root weld along the gap to configure a root layer while the inner circumferential surface side is unobstructed. After the root weld is complete, an outward thrust is applied along the inner circumferential surfaces of the conduits. During the application of the outward thrust, a filler weld is performed along the gap to fill the gap and to facilitate shrinkage of the filler and root weld materials longitudinally and radially outward while preventing pressing out of the filler and root weld materials radially inward of the inner circumferential surface.

Spiral forming devices, systems, and methods can be used to join edges of a of a stock material, in a curved configuration, along one or more joints to form tubular structures, such as conical and/or cylindrical structures (e.g., frusto-conical structures). A planar form of the stock material can be formed from a plurality planar sheets coupled to one another in an abutting relationship. By controlling relative orientation and shapes of the plurality of planar sheets forming the stock material and/or by controlling a position of a roll bender used to curve the planar form of the stock material into the curved configuration, the curved configuration of the stock material can be controlled through transitions between sheets to facilitate rolling the sheets to a desired diameter with a reduced likelihood of dimples or other errors and to facilitate fit up between adjacent sheets in the curved configuration.

The invention relates to long-dimensional flexible tubes (coiled tubing). There are several variants of the proposed basic pairs of an umbilical coiled tubing and include means of their production with multi-stage sequential shaping process of one or multiple strips at an estimated geometry, and where isolated channels, partitions and flanges are formed during this process. If required, longitudinal butts of an additional shaped longitude strips can be welded to them to form additional hydraulic channels of the umbilical coiled tubing which can be reeled up to a drum. Other types of service channels (electric, fiber-optic, capillary etc.) or standard coiled tubing can be placed inside or outside channels in the form of a service channels tape. Flanges located beyond the outside dimensions of an umbilical coiled tubing may have a wave-type of form. Connecting partitions may have holes intended for fingers of injector, for elevator, for service channels tape. Flanges and partition holes are weight-carrying members of umbilical coiled tubing. Welding seams, flanges, centers of a closed channels and partitions are located, mainly, on the middle line of an umbilical coiled tubing's cross-section. The umbilical coiled tubing makes it possible to significantly increase possibilities of coiled tubing units in technological operations as well as in artificial lift methods due to its multi-channel design and, consequently, multifunctionality.

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-10, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).

The invention relates to a method of manufacturing a pipe having a connecting flange, wherein the flange part is welded to an end face pipe end and at least one protrusion of the pipe or of the flange part is provided in the region of the flange hub and contacts the inner wall of the other part on the joining together of the pipe and the flange part to cover the formed weld joint to the pipe interior; and wherein finally the pipe and the flange part are welded to one another.

Provided is an electric resistance welded steel pipe or tube having excellent fatigue durability after rapid and short-time heating quenching treatment. An electric resistance welded steel pipe or tube comprises: a base metal being a steel sheet having a specific chemical composition and an electric resistance weld portion having a bond width of 4010.sup.6 m or more and 12010.sup.6 m or less, wherein C.sub.0-C.sub.1 is 0.05 mass % or less, where C.sub.0-C.sub.1 is a difference between C.sub.1 in mass % which is a minimum C content of the electric resistance weld portion and C.sub.0 in mass % which is a C content of the steel sheet, and a depth of a total decarburized layer in each of an inner surface layer and an outer surface layer of the electric resistance welded steel pipe or tube is 5010.sup.6 m or less.

Spiral forming devices, systems, and methods can be used to join edges of a of a stock material, in a curved configuration, along one or more joints to form tubular structures, such as conical and/or cylindrical structures (e.g., frusto-conical structures). A planar form of the stock material can be formed from a plurality planar sheets coupled to one another in an abutting relationship. By controlling relative orientation and shapes of the plurality of planar sheets forming the stock material and/or by controlling a position of a roll bender used to curve the planar form of the stock material into the curved configuration, the curved configuration of the stock material can be controlled through transitions between sheets to facilitate rolling the sheets to a desired diameter with a reduced likelihood of dimples or other errors and to facilitate fit up between adjacent sheets in the curved configuration.

Tube forming methods can be used for efficient transition in the production of tubes having varying thickness. Material used to form consecutive tubes may have the same thickness along a separation plane separating a first discrete section from a second discrete section of the material, and the first discrete section and the second discrete section may each have varying thickness in a feed direction of the material. With such a thickness profile, the first discrete section of the material may be formed into a first cylinder having varying thickness and separated from the second discrete portion as the second discrete section is formed into a second cylinder having varying thickness. In particular, the transition between the first cylinder and the second cylinder may be achieved without scrap and/or interruption, resulting in cost-savings and improvements in production throughput associated with forming tubes having varying thickness.

The present disclosure is directed to a stent manufacturing assembly including an inner shield, a patterned metal sheet, and an outer shield. The patterned metal sheet may include a polymer coating with an embedded therapeutic agent. The inner shield, patterned metal sheet, and outer shield are arranged in a layered configuration and placed in a stent rolling mechanism with a mandrel. In particular, the patterned metal sheet is disposed on the outer shield and the inner shield is disposed on the patterned metal sheet in the layered configuration. In the layered configuration, the stent manufacturing assembly is rolled by the rolling mechanism into a tubular shape and welded to form a tubular stent.