... black painting anti-corrosionPlace of originTianjinStandardBS, JIS, GB, DIN, ASTM, APIApplication Natural gas, petroleum, chemical industry, ... 8810-530*1.5-36Boiler pipes for refinery,heatexchangeing pipes,seamless steel pipes for pipelineHigh-pressureSeamless pipes for fertilizer making equipment20, ... 40Over-heat pipe for low and medium pressure boiler,boilling water pipe,locomotive somke pipe(big ...