It is not only used for conveying fluids and powdered solids, for exchanging heat, for making machine parts and containers, but also for making economical steel. The steel pipe is used to manufacture the construction structure grid, strut and mechanical support, which can reduce the light weight and save 20 ~ 40% metal, and realize the factory mechanization construction. Making highway bridge with steel pipe not only can save steel, simplify construction, but also can greatly reduce the area of coating protection, saving investment and maintenance costs.
