API 5L PSL2 is the implementation of pipeline steel pipe standards, the provisions of the pipeline delivery conditions. Pipeline steel pipe is used to extract the surface of the oil, steam, water and other transportation to the oil and gas industry enterprises pipeline. PSL2 in the chemical composition, tensile properties, impact work, non-destructive testing and other indicators are strict on the PSL1.API 5L PSL1 standard applies to fine grain killed steel.API 5L PSL1 standard main steel grade:X80,X70,X65,X60,X56,X52 and so on.