Questions about the straightness of stainless steel pipes

In the inquiry of the stainless steel pipe market, many people asked us about the straightness of the stainless steel pipe. In fact, stainless steel pipes have an extremely important share in the industry and are widely used in the chemical, metallurgical, and mechanical industries. Straightness is one of the main parameters for measuring the quality index of steel pipes. It is of great scientific significance and industrial value to study the accurate measurement of straightness of steel pipes. At home and abroad, there are many studies on the straightness measurement of workpieces such as shaft parts and guide rails, but there are few studies on the straightness measurement of steel pipes.

Then, regarding the straightness of the stainless steel pipe, the 304 stainless steel pipe manufacturer will come to you slowly. In fact, in the process of production and processing of the stainless steel pipe, the pipe body will appear in different degrees in the longitudinal direction (ie, the length direction), but only The degree of curve of some steel pipe products can be visually seen by the naked eye. Such curved steel pipes are already unqualified products. As long as they are regular manufacturers, such products are absolutely not allowed to leave the factory; some stainless steel pipes require special instruments. The degree to which the device measures its straightness is expressed by numbers, that is, the bending of the steel pipe or the straightness of the steel pipe.

For the straightness of steel pipe, the standard is not high in the pipeline for general fluid transportation. This pipe mainly requires the concentricity of the nozzle. The wall thickness of the pipe is not too eccentric, so as to facilitate the welding of the pipe. However, if stainless steel pipes are used on processing machinery, especially rubber rollers, center shafts, guide rails, etc., they have high requirements for straightness or curvature, and this is also a very important indicator for them. Because this is mainly related to the problem of the processing volume of a later product, the size of the processing directly affects the production cost. If the processing is not done, the steel pipe may become a waste product. Therefore, manufacturers like the production of roller equipment pay special attention to the straightness detection of steel pipes when purchasing stainless steel seamless pipes or stainless steel welded pipes. In the case of forced lasting: if it is a small-diameter steel pipe, it may use precision-rolled precision stainless steel pipe; if the finish rolling can't be done, only the large-diameter non-standard stainless steel thick-walled pipe can be selected, and go back through the lathe for finishing. To achieve the straightness and brightness of the finished product.

The following mainly introduces the conventional straightness measurement method:

First, the stainless steel seamless pipe or welded pipe steel pipe local bending degree: that is, the ruler with a length of one meter depends on the maximum bending of the steel pipe, and the chord height (mm) is measured, which is the local bending value, the unit is mm /m, indicating a method such as 2.5mm/m. This method is also applicable to tube end bending.

Second, the total bending length of the steel pipe: use a string, pull from the two ends of the pipe, measure the maximum chord height (mm) of the bending of the steel pipe, and then convert into the length (in meters) percentage, which is the length of the steel pipe The full length of the direction of curvature. For example, if the length of the steel pipe is 10m and the maximum chord height is 30mm, the full-length bending of the pipe should be: 0.03÷10m×100%=0.3%. For the steel pipe with high straightness requirement, our factory has professional testing equipment. To detect. The precision stainless steel tube produced by our factory can reach a straightness of 0.1mm/m after straightening, and this high-precision stainless steel tube is widely used in precision instruments and precision machinery with high straightness requirements.