steel pipe for construction 1)OD:4mm-50mm; WT: ... resistant,Low temperature-resistant, corrosion-resistant Seamless pipe for Petroleum, chemical, electric power,Boiler industry16-824 ... line pipe 5L GR.B, X52,X60 API-for petroleum,natural gas, industrial dilivery(gas,water,oil) ... iron pipe-ironGB/T13295-2003 ISO2531/2003- Public works, mining, textile, electric power, boilers, drinking water, machinery ...