Steel pipe can be divided by cross-sectional shape

　　Special-shaped steel pipe refers to all kinds of circular cross section of the steel pipe. Steel pipe according to the profile shape is divided into: such as cross section steel tube and variable cross section steel tube. Variable cross-section or variable cross-section steel pipe refers to the cross section shape along the length direction, both inside and outside diameter and wall thickness change periodic or aperiodic steel pipe. Its mainly include: tapered tube, tapered tube inside and outside ladder pipe, the ladder, deformed pipe, corrugated pipe, ASME Carbon Spiral Steel Pipes, steel tube with heat sink, and with double line of barrel, etc.