... 5L/CT21.3-813*1.5-40Carrying gas,water or oil in the industries of petroleum and natural gasHydraulic ... 377*9-40Hydraulic support and prop1.Surface Treatment:Transparent oil or black painting anti-corrosion2.Application:Natural gas, petroleum, ... chemical industry, electric power, metallurgy thermodynamic fields, water supply engineering, steam heating, hydroelectric power station and long ...