Devices, systems, and methods are directed to formation of tubular structures, such as spirally formed structures, having spirally extending reinforcing material. In particular, tubular structures can be formed in a continuous process in which a first material is spiral formed along a first spiral and a second material is joined to the first material along a second spiral to reinforce the spirally formed first material. As compared to manual application of reinforcing material, such a continuous process can facilitate producing tubular structures at rates suitable for high-volume, commercial fabrication. Further, or instead, as compared to the use of circumferentially extending reinforcing material to support a spiral formed tube, reinforcing the spirally formed first material with a spiral of the second material may offer certain structural advantages, such as improved resistance to buckling.

The present invention relates to a spiral tube capable of improving resistance performance against a collapse load generated by the difference between an internal pressure and an external pressure, while having a reduced thickness, the spiral tube comprising: a tube body in which a strip is connected in a spiral shape and welded at the front end thereof; and a stiffener provided on the inner surface of the tube body.

Embodiments of a large container may include a container base and a circumferential container wall. An upper end of the wall is closed by a container cover in the form of a metal disc. An annular, circumferential support element is secured at an upper end region of the wall. The disc spans the upper open end of the container wall. A lower side of the disc is welded to the support element and/or to the upper end region of the container wall by a continuous first welding seam. An upper side and/or an edge of the disc is welded to the support element by a continuous second welding seam. The first and second weld seams have respective first and second roots which merge into one another or at least come together.

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.

A high temperature iron-chromium-aluminium (FeCrAl) alloy tube extending along a longitudinal axis, wherein the tube is formed from a continuous strip of a high temperature FeCrAl alloy and comprises a helical welded seam. The high temperature FeCrAl alloy tube is manufactured by feeding a continuous strip of the high temperature FeCrAl alloy toward a tube shaping station, helically winding the strip such that long edges of the strip abut each other and a rotating tube moving forward in a direction parallel to its longitudinal axis is formed, and continuously joining said abutting long edges together in a welding process directly when the tube is formed, whereby a welded tube comprising a helical welded seam is obtained.

An apparatus and a method for producing strip wound tube products are disclosed. The apparatus includes a winding machine for winding a strip to a strip wound tube and a finishing machine for cutting off pieces of desired length from the strip wound tube and for connecting strip layers in the end sections of the strip wound tube product by way of an joining operation, the finishing machine having a mobile operating head and/or a force decoupling unit.

A high temperature iron-chromium-aluminium (FeCrAl) alloy tube extending along a longitudinal axis, wherein the tube is formed from a continuous strip of a high temperature FeCrAl alloy and comprises a helical welded seam. The high temperature FeCrAl alloy tube is manufactured by feeding a continuous strip of the high temperature FeCrAl alloy toward a tube shaping station, helically winding the strip such that long edges of the strip abut each other and a rotating tube moving forward in a direction parallel to its longitudinal axis is formed, and continuously joining said abutting long edges together in a welding process directly when the tube is formed, whereby a welded tube comprising a helical welded seam is obtained.

A control system for forming a tapered structure includes a sensor providing feedback for a machine for forming a tapered structure including at least three rolls having at least one bend roll and at least two guide rolls. The guide rolls may include rollette banks having a plurality of rollettes. The machine may also include an adjustment mechanism to position at least one of the rolls, where a diameter of the tapered structure being formed is controlled by relative positions of the rolls. The machine may also include a joining element to join edges of a stock of material together as it is rolled through the rolls to form the tapered structure. The control system may also include a controller to receive feedback from the sensor and to send a control signal based on the feedback to the adjustment mechanism for positioning at least one of the rolls.

A steel product includes the following chemical composition in wt. %: C: 0.01 to <0.3, Mn: 4 to <10, Al: 0.003 to 2.9, Mo: 0.01 to 0.8, Si: 0.02 to 0.8, Ni: 0.005 to 3, P: <0.04, S: <0.02, N: <0.02, with the remainder being iron including unavoidable steel-associated elements, wherein an alloy composition satisfies the equation 6<1.5 Mn+Ni<8; or the equation 0.11<C+Al<3, or an alloy composition contains, in addition to Ni, at least one or more of the elements, in wt. %, B: 0.0005 to 0.014; V: 0.006 to 0.1; Nb: 0.003 to 0.1; Co: 0.003 to 3; W: 0.03 to 2 or Zr: 0.03 to 1. The steel product has a microstructure of 2 to 90 vol. % austenite, less than 40 vol. % ferrite and/or bainite, with the remainder being martensite.

Spiral forming methods can be used to join edges of a rolled material along a spiral joint to form conical and/or cylindrical structures. Alignment of the edges of the rolled material can be controlled in a wrapping direction as the material is being joined along the spiral joint to form the structure. By controlling alignment of the edges of the material as the edges of the material are being joined, small corrections can be made over the course of forming the structure facilitating control over geometric tolerances of the resulting spiral formed structure.