GB/T8163-2008 seamless steel pipe: 1.Raw material:hight quality ... :2.5mm-75mm 3.Grade:201,301,316,316L,401 GB/T8163-2008 seamless steel pipe 1 Material CARBON STEEL STEEL ... .The exhaust purification device5.Construction and ornament 10Audited API,BS,GB GB/T8163-2008 seamless steel pipe