Large diameter thick wall steel pipe used primarily as a place of mechanical processing, production of the fuel tank! Usually more than the outer diameter of the large diameter thick wall steel pipe 200mm, wall thickness more than 20mm of steel pipes, the largest diameter can reach 1220mm and wall thickness can reach 80mm.
The production technology of large diameter thick wall steel pipe generally includes hot-rolled, hot rolled, casting and other production methods! The large diameter thick wall steel pipe more common in double-sided submerged arc welding production process, product by bending, commissure, welding, outside welding, straightening, first-class multi-level process, to achieve the American Petroleum Institute standard requirements. The large diameter thick wall steel pipe used in more than a large steel structure construction, to do the main support section, for example, a bridge piling, the undersea piling, high-rise buildings piling. The material is generally used Q345B, Q345C. Lower temperature region will be used Q345D Q345E.