2、 按断面外形分类:(1)圆形钢管;(2)矩形管。3、 按壁厚分类-

2, a cross-sectional shape classification according to: (1) a circular pipe; (2) a rectangular tube. <br>3, the classification by thickness - a thin-walled steel pipe, thick-walled pipe <br>4, by use classification: <br>(1) sub-tubes civilian tube, rectangular tube, perforated pipe, generally used for decorative aspect, building, structure or the like; <br>(2) industrial pipe: steel pipe for industry, steel pipe for general (water pipe), construction machinery / fluid delivery tube, the heat exchange tube boiler, food hygiene tubes. Generally used in various fields of industry such as: petrochemical, paper, nuclear power, food, beverage, pharmaceutical and other industries demanding a fluid medium pipeline.

2, according to the shape of the section classification: (1) round steel pipe;<br>3, according to the wall thickness classification - thin-walled steel pipe, thick-walled steel pipe<br>4, by use classification:<br>(1) Civil pipe sub-round tube, torque pipe, flower tube, generally used in decoration, construction, structure and so on;<br>(2) Industrial pipe: industrial pipe for distribution, steel pipe for general pipe (drinking water pipe), mechanical construction / fluid conveyor pipe, boiler heat exchange pipe, food hygiene pipe, etc. Generally used in various fields of industry such as: petrochemical, paper, nuclear energy, food, beverage, medicine and other industries on the fluid medium requirements of higher pipeline.

2. According to the section shape classification: (1) circular steel pipe; (2) rectangular pipe.<br>3. Classification by wall thickness -- thin wall steel pipe, thick wall steel pipe<br>4. Classification by use:<br>(1) Civil pipe is divided into round pipe, rectangular pipe and flower pipe, which are generally used in decoration, architecture, structure and other aspects;<br>(2) Industrial pipe: steel pipe for industrial piping, steel pipe for general piping (drinking water pipe), mechanical structure / fluid transmission pipe, boiler heat exchange pipe, food hygiene pipe, etc. Generally used in various fields of industry, such as petrochemical industry, papermaking, nuclear energy, food, beverage, medicine and other industries, which have high requirements for fluid medium.<br>