Welded steel pipe forming method

Welded steel pipe is the use of different types of steel through the process of shaping the way the bending process and so welded pipe products for a class, however, because the type of welded steel pipe market is very diverse, so the molding method is also very diverse, welding the main pipe forming method under which workers have several types.

1, single radius molding

Single radius of roll forming method has circumferential bending molding, curved edges and the center of the curved molding three molding method, a single radius molding method is: pass by a single radius composed of horizontal roll forming machine, vertical rolls are arranged alternately, strip from horizontal roller, vertical roll through the middle, gradually curved plate into the tube.

2, circular curved molding

At the same time the whole width direction of the strip bending deformation of the frame forming the bending radius decreases; margin of the curved molding is bent from the strip edge portion, the bending radius is constant, gradually increasing angle of the deformation, to reduce the intermediate portion of the strip width until the strip into a circular closed; molding method from the center of the bending center portion of the beginning of the bending deformation of the strip, the bending radius is constant, gradually extended to the side edges, into a round until closed.

3, double radius molding

Deformation using a combination of two or more basic deformation method, but the application is more edge molding method + circumference molding. Integrated with the circumference of the tube edge deformation molding method, pass it to squeeze roll radius or radius edges finished pipe bending radius, the bending the strip edges to a deformation angle and subsequent molding vehicles remained unchanged, curved intermediate portion of the strip forming press the circumferential bend-shaping method for forming distribution.

4, W molding

Paragraph a rough-shaping the previous frame with W or anti curved curved shape, the forward edge portion of the strip is bent in the middle part of the reverse bend, increasing the arc length of the bending edge portion, the edge deformed sufficiently during the molding tube the height difference is small, relative to the edge extending substantially reduced to avoid the bulge caused by the elongation of the longitudinal edges while reducing the peripheral speed difference.

5, row roll forming

In order to avoid a general continuous strip molding machine molding strip edges occur when the relative extension and vertical rebound deformation between horizontal molding roll continuous configure many small rolls, to replace the general level of forming rolls, the strip edges can conducted along a smooth natural deformation away. These mounted in a cage in the small roller frame becomes row roller. General roll forming machine consists of a pre-roll bending, a set of row roller device, two finishing roller. Suitable for relatively thin-walled steel pipe forming.

6, TPF three-point bending molding

Longitudinal using some denatured according to the law of molding, using the first "W" shaped the bending the strip edges; said second horizontal roll bending the strip to the strip central "U" shape; the third horizontal roll bending "U "Two straight edge, so close to double the radius section and into the vertical roll strip were rounded team deformation.

7, UO molding

The steel sheet according to the requirements of a pre-edge the bending machine using the U and O, two molded molding machine, an O ring for forming the compressive deformation (0.2% - 0.4%), the opening to the pipe circumferential residual stress uniform. Then the O-shaped tube welded cold after expanding. It features large capacity, annual production capacity of 30 to 100 tons, suitable for a single large-scale production, greater investment.

8, JCO forming

Progressive bending pressure plate forming the first half of the J-shaped pressed into the other half of the steel plate and then pressed into a J-shaped, the C-shaped formation after repeated compression, the final pressure of the tube-shaped opening O is formed from the middle. Then O sex tube links cold expanding. Steel production flexibility, especially for the production of thick-walled tube diameter, and less investment.

9, RB molding

After several rolled steel plate the bending rolls between three and four rolls, ultimately bent into a cylindrical shape desired. The process appeared earlier, and more for the production of larger outer diameter (up to 4500mm), shorter length (3 ~ 6m) pressure vessel, structural tubes and pipes, dimensional accuracy is poor, lower capacity.

10, before the pendulum spiral welded pipe forming

The front molding strip swinging to adjust the angle of the molding. Unit no Looper, small footprint, but only intermittent production (roll-to-roll or head parking).

11, the pendulum spiral welded pipe forming

After the former steel swing bridge to adjust molding angle. Typically a looper to ensure continuous production, covering more, more equipment.