3.1. The domestic seamless pipe supplied according to the mechanism performance shall be made of ordinary carbon steel according to class a steel of GB / t700-88 (but the sulfur content shall not exceed 0.050% and phosphorus content shall not exceed 0.045%), and its mechanical properties shall comply with the values specified in the table of gb8162-87.
3.2 the domestic seamless pipe supplied according to the hydrostatic test must ensure the hydrostatic test specified in the standard.
3.3 the physical property inspection of imported seamless pipes shall be carried out in accordance with the relevant standards specified in the contract.
2. Use 2.1. Seamless pipe is widely used. Seamless pipes for general purposes are rolled by ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output. They are mainly used as pipes or structural parts for conveying fluid.
2.2. Supply is divided into three types according to different purposes: A. supply according to chemical composition and mechanical properties; b. Supply according to mechanical properties; c. Supply according to 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.
2.3 seamless pipes for special purposes include seamless pipes for boiler, geological and petroleum.
3.1 according to different production methods, seamless steel pipe can be divided into hot-rolled pipe, cold-rolled pipe, cold drawn pipe, extruded pipe, etc.
3.2. According to the shape, there are round pipes and special-shaped pipes. In addition to square and rectangular tubes, special-shaped tubes also include elliptical tubes, semicircular tubes, triangular tubes, hexagonal tubes, convex tubes, quincunx tubes, etc.
3.3. According to different materials, it is divided into ordinary carbon structural pipe, low alloy structural pipe, high-quality carbon structural pipe, alloy structural pipe, stainless pipe, etc.
3.4 according to special purpose, there are boiler tubes, geological tubes, oil tubes, etc.
Post time: Mar-08-2022