1. Distinguish
straight seam steel pipes according to the outer diameter
The outer diameter between φ4.76-φ12.70 mm is fine-diameter straight seam steel pipe; the outer diameter between φ13-φl14 mm is small-diameter straight-seam steel pipe; the outer diameter is between φ114-φ406 mm is medium-diameter Straight seam steel pipe; large diameter straight seam steel pipe with an outer diameter greater than φ406 mm.
Second, according to the size of the wall thickness to distinguish welded pipes
According to the ratio of wall thickness t to steel pipe outer diameter D, welded pipes can be divided into the following five categories:
① t/D less than 2% is an extra thin-walled tube;
② t/D is equal to 2-5% for thin-walled tubes;
③ t/D greater than 5-12% is ordinary wall original pipe;
④ t/D greater than 12-18% is a thick-walled tube;
⑤ t/D greater than 18% is the original wall tube.
Thin-walled pipes, common-walled pipes, and thick-walled pipes are not conceptually distinguished by the value of the wall thickness. However, some standards have three different wall thicknesses corresponding to the same outer diameter. The pipes of these three wall thicknesses may be named thin-walled pipes, ordinary wall-thickness welded pipes, and thickened straight seam steel pipes in this standard.
Because of the special functions such as corrosion resistance, anti-oxidation ability, anti-static, etc. of the longitudinal seam welded pipe, as well as the elegant appearance and durability of the longitudinal seam welded pipe, it has gradually become a trend to use it to make some machinery, components, and springs. With the continuous maturity and stability of the technological process, the industrial product longitudinal seam welded pipe, which has been developing and growing in recent years, is gradually penetrating various fields such as practical hardware and the architectural decoration industry with its advanced performance and polynomial functions. . And as people become more and more familiar with it, its demand will become more and more rapid, and its application field will also become wider and wider. Another example is the wide application of welding rods and a large number of stainless steel components, connectors, etc., and its field has also been widely occupied by longitudinal welded pipes. In addition, along with the full-line development and rational use of high-tech products, the application range of longitudinal welded pipes has also been further expanded. Many industries that need to be updated have adopted longitudinal welded pipes, especially in the chemical industry and chemical fiber industries. Industrial equipment transformation.
