Sales of corrosion-resistant and insulated pipes, steel pipes, steel structures, structural pile pipes, high- and low-pressure pipe fittings, high- and low-pressure flanges, elbow fittings, coupling devices, caps, compensators, valves for use in pipelines, wind doors, pipe clamps, concrete pump components, pump pipes, rubber hoses, wear-resistant pipes, lined pipes, dual-metal composite pipes, support and suspension brackets, gaskets, and chemical components for pipelines.