Steel pipe is a kind of hollow long round steel, which is widely used in petroleum, chemical, medical, food, light industry, mechanical instrumentation and other industrial transportation pipelines and mechanical structural parts. In addition, when the bending and torsion strength are the same, the weight is lighter, so it is also widely used in the manufacture of mechanical parts and engineering structures. The steel pipe has excellent flexibility. The flexibility of polyethylene allows polyethylene pipes to be coiled and supplied in longer lengths. There is no need for various connecting pipes, and its direction is easy to change in accordance with the requirements of the construction method. It is also possible to change the steel pipe before construction. Shape, restore the original size and dimensions after inserting the old tube.

Welded steel pipes have higher bending and torsion resistance and greater load-bearing capacity, so they are generally widely used in the manufacture of mechanical parts. For example, oil drill pipes, automobile drive shafts, bicycle frames, and steel scaffolding used in construction are all made of welded steel pipes. However, seamless steel pipes can be used as pipes for conveying fluids because they have a hollow cross-section and a long strip of steel with no joints on the periphery. For example, it can be used as a pipeline to transport oil, natural gas, gas, water, etc. In addition, the bending strength of seamless steel pipes is relatively small, so they are generally widely used in low and medium pressure boiler superheated steam pipes, boiling water pipes and locomotive boiler superheated steam pipes. In short, through the classification of uses, welded steel pipes and seamless steel pipes can be clearly distinguished.

The forming process of seamless steel pipes and welded pipes is mainly different. Welded pipes are generally welded by bending a flat sheet, and you can find a weld on it; the thicker diameter is usually a spiral weld. However, seamless steel pipes are generally formed by squeezing the molten steel through an annular slit and then undergoing processing processes such as stretching, so that there is no weld. This is the difference between seamless pipes and welded pipes with the naked eye.

The steel pipe has good ability to resist scratches. Studies have proved that PE80 grade polyethylene pipe has better resistance to SCG and scratch resistance. PE100 polyethylene Yantai steel pipe material has better resistance to scratches. Shenlong steel pipe also has good resistance to rapid crack transmission. Polyethylene has excellent resistance to the rapid propagation of cracks. Aiming at the characteristics that the lower the temperature, the larger the pipe diameter and wall thickness, the higher the working pressure, and the greater the risk of rapid cracking of plastic pipes.