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 method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.

The invention relates to a flexible pipe carcass comprising a flexible tubular wall structure comprising a helically wound wall strip; wherein interlocking sections of successive windings of said wall strip form the wall structure. The interlocking sections of adjacent wall strips define a length and are movable with respect to each other between a first position and a second, extended position for changing said length, the interlocking sections being formed such that in the extended position a carcass gap is provided between adjacent interlocking sections for accommodating relative movement there between upon flexure of the wall structure. An insert profile is located in the carcass gap of the tubular wall structure on an inside of the wall structure to at least partly cover the carcass gap.

Feeding stock used to form a tapered structure into a curving device such that each point on the stock undergoes rotational motion about a peak location of the tapered structure; and the stock meets a predecessor portion of stock along one or more adjacent edges.

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 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.

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 first roller dies will perforate, puncture the metal strip after the strip goes through the front guide. After the perforation the metal strip can then be corrugated. This is an improvement over punching the metal strip. Punching the metal, rotary punch, requires and extra step and leaves metal scrap, which is why punching metal for the first rolls would clog the machine and cause damage to the machine. The results of these tiny holes in the cylindrical duct help muffle the vibration and other noises from the motorized fan down the ductwork. The cylindrical perforated duct acts like a muffler. Air conditioning, bathroom exhaust fans, kitchen exhaust fans noise can me great reduced cheaply and efficiently. This perforated duct will be used with a vapor barrier and/or insulation.

An elongate tape element, a flexible pipe body and method of producing a flexible pipe body are disclosed. The tape element (508) has a cross-sectional profile comprising a body portion (510) for being positioned between collapse resistant tape windings (501) such that each body portion (510) lies at least partially in a gap (512) between adjacent collapse resistant tape windings (501); and at least one wing portion (516) extending from an end region of the body portion, the at least one wing portion configured to span the gap and respectively abut with a radially inner surface of an adjacent collapse resistant tape winding.

A method for creating a tapered spiral welded conical structure where the overall shape of the cone is first graphically slit axially and unwrapped, and then a series of construction arcs and lines are created to form the edge lines of a strip that can then be wrapped (rolled) to form a tapered conical structure. The edges of the spirally wound strip can be welded together, and a very large conical structure can thus be achieved. Various construction options are presented from a constant width strip to strip made from straight segments. Equations are given for the formation of the strips to enable those skilled in the art of spiral welded tubing to practice the invention.