Pipe straightening machine

Product Description

The six roller steel pipe straightening machines is used for straightening of steel pipes (including welded and seamless steel pipes) with bending defects to meet the requirement on straightness of products.



They are normally of 2*2*2 layout with variant of 2*2*2*1 layout for special requirements.



The 2*2*2 type straightening machines have three pairs of contra-positioned transmission straightening rolls which press the steel pipes to be straightened between the pairs of rolls and drive them to move forward while rotating (spiral motion)successively through the three pairs of straightening rolls to become straight.



The straightening process is realized through two different effects. One is the bending effect which is realized by adjusting the second pair of rolls to a slightly higher level than the first pair to allow a straightening effect to occur at a small fraction in the middle of the pipe subject to elastic-plastic deformation due to bending; the other effect is the straightening effect formed due to the local flattening deformation and the plastic deformation of the area in the cross section of the pipe. The satisfactory straightening of steel pipes can be obtained through the combination of the bending effect and flattening effect.



It should be noted that there are blind zones of straightening at two ends of steel pipes.



The straightening machines developed by this company have their straightening rolls designed according to the maximum diameter of steel pipes to be straightened. When straightening a pipe with the maximum diameter ,the angle of inclination of straightening rolls is adjusted to **0 in order to get the full contact of the pipe with the entire length of the rolls while when straightening a pipe with smaller diameter, the inclination of straightening rolls is adjusted to an appropriate angle smaller than *0o so that the pipe contacts with the rolls at 3 points at the waist circle and the two ends with very small clearances at other points provided that the range of diameters of the pipes to be straightened is not to large, such small clearances will be covered by the straightening deformation of the pipes without causing any visible straightening indentation.



The damage to pipes caused by waving of pipe ends and lead-in of pipes during process of straightening can be avoided by using front and rear equipment specially designed and quick start device of straightening rollers.We are in a position to supply machines of different configurations .for example, we can provide both ordinary welded pipe production lines and heavy straightening machines for API thick-wall high gradel pipes with straightening force up to hundreds of tons; we can produce both small machines for straightening *0mm tubes and large straightening machines for straightening pipes up to **5mm; We can provide both ordinary products with manual adjustment of roll spacing and roll angle and high-grade products with force sensors (for measuring flattening force and bending force),displacement sensors and computer fully automatic adjustment.