Steel pipes made from a single piece of metal without seams on the surface are called seamless steel pipes. According to the production method, seamless pipes are divided into hot rolled pipes, cold rolled pipes, cold drawn pipes, extruded pipes, and top pipes. According to the cross-sectional shape, seamless steel pipes are divided into two types: round and special-shaped. Special-shaped pipes have square, elliptical, triangular, hexagonal, melon-shaped, star-shaped, and finned pipes. The maximum diameter is 650mm and the minimum diameter is 0.3mm. According to different purposes, there are thick-walled pipes and thin-walled pipes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, petrochemical cracking pipes, boiler pipes, bearing pipes, and high-precision structural steel pipes for automobiles, tractors, and aviation.
A steel pipe with no joints along the perimeter of its cross section. According to different production methods, it can be divided into hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe, pipe jacking, etc., all have their own process regulations. The materials are ordinary and high-quality carbon structural steel (Q215-A～Q275-A and 10～50 steel), low alloy steel (09MnV, 16Mn, etc.), alloy steel, stainless and acid-resistant steel, etc. According to the purpose, it is divided into two types: general purpose (used for water, gas pipelines and structural parts, mechanical parts) and special purpose (used for boilers, geological prospecting, bearings, acid resistance, etc.).
Seamless steel pipes are widely used. 1. General-purpose seamless steel pipes are rolled from ordinary carbon structural steel, low-alloy structural steel or alloy structural steel, with the largest output, and are mainly used as pipelines or structural parts for conveying fluids. 2. According to different purposes, it is divided into three types of supply: a. According to chemical composition and mechanical properties; b. According to mechanical properties; c. According to water pressure test. Steel pipes supplied according to categories a and b, if used to withstand liquid pressure, shall also undergo a hydraulic test. 3. Special-purpose seamless pipes include seamless pipes for boilers, chemical and electric power, seamless steel pipes for geology, and seamless pipes for petroleum.
Seamless steel pipes have a hollow section and are used in large quantities as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, steel pipe is lighter in flexural and torsional strength and is an economical section steel.
Widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and construction used in steel scaffolding steel ring parts, can improve the material utilization, simplify the manufacturing process, save material and processing hours, has been widely used in the manufacture of steel pipe.
The above information is provided by steel pipe manufacturer.