Standard: GB, ASTM, API Outer Diameter: 18 - 460 mm Thickness: 3 - 60 mm ... -4.5 line pipe 5L GR.B, X52,X60 API-for petroleum,natural gas, industrial dilivery(gas,water,oil) ... ductile iron pipe-ironGB/T13295-2003 ISO2531/2003- Public works, mining, textile, electric power, boilers, drinking water, machinery, military ... decoration, construction20*20-500*500 Boiler Seamless Carbon Steel Pipes