Seamless steel pipe has a hollow cross section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with solid steel such as round steel, steel pipe is lighter in weight when it has the same bending and torsional strength.
Widely used in the manufacture of structural parts and mechanical parts, such as petroleum drill rods, automobile transmission shafts, bicycle frames, and steel scaffolding used in building construction. Man-hours have been widely used to manufacture steel pipes.
The use of seam steel pipes is very wide.
1. General purpose seamless steel tubes are rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output, mainly used as pipelines or structural parts for conveying fluids.
2. It is divided into three categories according to different uses: a. Supply according to chemical composition and mechanical properties; b. Supply according to mechanical properties; c. Supply according to hydraulic test. For steel pipes supplied according to categories a and b, if they are used to withstand liquid pressure, a hydraulic test is also required.
3. Special-purpose seamless pipes include boiler seamless pipes, chemical and electric power, geological seamless steel pipes and petroleum seamless pipes.