Seamless pipe (SMLS) is a steel pipe that is perforated from a whole round steel and has no welds on the surface. Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemicals, boiler pipes, bearing pipes and high-precision structural steel pipes for automobiles, tractors and aviation.
LSAW steel pipe is a straight seam submerged arc welded steel pipe. It is a pipe material produced by pressing (rolling) a single medium and thick plate into a tube blank in a mold or a forming machine, using double-sided submerged arc welding and expanding its diameter. . LSAW steel pipe has a wide range of finished product specifications, and the weld has good toughness, plasticity, uniformity and compactness, and has the advantages of large pipe diameter, pipe wall thickness, high pressure resistance, low temperature resistance and strong corrosion resistance. In the construction of high-strength, high-quality long-distance oil and gas pipelines, most of the steel pipes required are large-diameter thick-walled straight seam submerged arc welded pipes.
1. Different process
The biggest difference between the straight seam steel pipe and the seamless pipe in the production process is that the straight seam is that the steel pipe is flattened by coiling and then welded by electric resistance welding or submerged arc welding. There is a longitudinal weld. The seamless steel pipe is made by piercing the round steel and hot rolling or cold drawing, and there is no weld.
2. Different practicability
In practical terms, straight seam steel pipes are mainly used for low-pressure fluid transportation, low-pressure gas transportation, and mine drainage and so on. The pressure bearing of seamless steel pipe is greater than that of straight seam steel pipe, so it is generally used for high-pressure fluid transportation, such as gas cylinder pipes, diesel engines, oil pressure pipes, etc., and some of them act on steel structures.
3. Different prices
Because the production process of seamless steel pipe is more complicated and the price is relatively expensive compared with seam steel pipe, the seam steel pipe is mainly welded by steel plate (steel strip), which is simple in operation, fast in production efficiency, cheaper and more widely used.
