Seamless steel pipe is defined as a steel pipe made of a whole piece of metal without joints on the surface. According to the production method, seamless pipe is divided into hot rolled pipe, cold rolled pipe, cold drawn pipe, extruded pipe, pipe jacking, etc. According to the section shape, seamless steel pipes are divided into circular and special-shaped pipes. Special-shaped pipes have a variety of complex shapes such as square, oval, triangular, hexagonal, melon seed, star and winged pipes.
Seamless steel pipes are made of ordinary and high-quality carbon structural steel, low alloy steel, alloy steel, stainless and acid resistant steel, etc. According to the purpose, it is divided into general purpose and special purpose. Seamless steel pipes for general use are rolled by ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with large output. They are mainly used as pipes or structural parts for conveying fluid.
Seamless steel pipes are supplied in three categories according to different purposes: A. according to chemical composition and mechanical properties; b. Supply according to mechanical properties; c. Supplied as per hydrostatic test. If the steel pipe supplied according to class A and B is used to bear liquid pressure, it shall also be subject to hydrostatic test. 3. Seamless pipes for special purposes include seamless pipes for boilers, chemical and electric power, seamless steel pipes for geology and seamless pipes for petroleum.
Seamless steel pipe has hollow section and is widely used as pipeline for conveying fluid, such as pipeline for conveying oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipe has the same flexural and torsional strength and lighter weight. It is an economic section steel.
It is widely used to manufacture structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel scaffold used in construction. It can improve material utilization, simplify manufacturing process, save materials and processing hours. It has been widely manufactured with steel pipe.
