Straightness measurement is an important index to test the quality of steel tube. The straightness of steel pipes used in different industries is also different. Some are strict and loose, although for the current production technology, steel pipe can be well controlled. Straightness, but in the actual process, the straightness of steel pipe is actually measured, so that the best construction scheme can be implemented according to the degree of bending.


For the straightness of steel pipe, the standard of pipeline conveying fluid is not high. The concentricity of the nozzle is needed to facilitate the welding of the pipeline. However, if steel pipes are used in processing machinery, especially rubber rollers and central axles, they require high straightness or curvature, which is also a very important indicator for them. Because it involves processing capacity, processing capacity directly affects the size of production costs. If it is not processed, the steel pipe will be wasted directly. Therefore, manufacturers of drum production equipment should pay special attention to the straightness detection of steel tubes when purchasing seamless or straight seam steel tubes.


For seamless steel pipe, straight seam steel pipe and forged steel pipe, straightness is preferred to multiple forged steel pipe. Because the outside diameter of the processing equipment is very small, straightness is usually not a problem. Secondly, the seamless steel pipe is straightened by three rollers in the steel pipe production process, which basically meets the straightness requirements of customers. The worst is the linear steel pipe. Although the basic process also has this process, it is all made of steel or coil steel. If the internal stress of steel can not be released well, the steel tube will be deformed after processing.


There are two common methods for calculating straightness or curvature:
Firstly, the local bending of seamless or straight seam steel pipe: that is, the length of the scale of 1 meter depends on the maximum bending degree of the steel pipe, and the chord height (mm) is measured, which is the local bending value in mm. / m, representing the method of 2.5mm/m. The method is also applicable to pipe end bending.


Second, the total bending length of the steel pipe: pull out from both ends of the pipe with a rope, measure the maximum chord height (mm) of the steel pipe bending, and then change the percentage of the length (m), that is, the full length curvature of the length direction of the steel pipe.