Spiral welded seam is to produce a large-diameter steel pipe is very cost-effective method. In recent years, the annual output of welded steel pipes 65% of annual production. The annual production of spiral seam welded steel pipe accounts for about 5-10% of annual production, plays an important role in the national economy. Pipe is widely used in pipelines: transportation of oil, natural gas, water gas, coal, liquid, gaseous and solid media; for construction and marine structures such as foundation piles, cofferdam; pressure vessels and pipes, heat and power plant exhaust pipe gray tubes.

When forming roll up the tube, it can bite spot welding, shaper short, under various diameter pipe elevation change, so the support rollers, runout and other ancillary equipment is relatively simple, easy to manufacture, easy to adjust, small civil works, but the height of the welding head with the pipe diameter to change the lift. When the volume inside the welding head device is simple, it can be more easily quit within the weld head replacement conductive tip, and do not cut the hole in the pipe, which saves the pipe, but also saves time. When the bite spot welding, since the factors strip crescents curved molding and other changes affecting the geometrical conditions when forming the seam nip point change, you should use the weld gap automatic control of advanced technology, in order to ensure the quality of welding.

Scroll down when forming tube, in addition to engaging in high-frequency welding point, the second pitch submerged in forming seam welded, soldered the first pitch in the second molding seams, if due Tsukigata changing the bend and other geometric conditions and changes affecting the sew molding nip point, then the second pitch forming solder joints reflect at "less sensitive" - ​​or said to reflect "slow" and therefore difficult to use trim molding technology to improve the quality of solder joints formed at. And on the volume compared to the support roll runout, inner welding head mechanism has a corresponding disadvantage - the disadvantage of producing a volume on the advantages of lower volumes.

Sleeve shaper works: the delivery of the strip feeding machine after input guides or guide, at a certain angle molded into the sleeve shaper to form a spiral pipe(ssaw steel pipe). Strip tangentially into the sleeve forming, so as to reduce the strip forming the inner wall of sleeve friction, but in the former strip resistance is still large, they tend to make the strip outwardly convex hull causing the outer surface of the serious scratch, affect product quality. In the actual production process, forming angle can consciously less than the calculated theoretical point of view, to cause the forming tube diameter than the diameter of the sleeve molding slightly smaller. This will reduce friction, saving power. This molding is suitable for the manufacture of small diameter pipe. Its advantages are: simple to manufacture, low cost. Easy operation and control, adjust the replacement work and small size. The disadvantage is molded liner wear severe, life is short, the energy consumption.