Seamless steel tube for gas cylinder:
 1. tested piece by pieceaccording to GB/577-1996(test procedures of Ultrasonic for seamless steel tube),meeting C5 class,
2. Non-metallic inclusion is evaluated by JK method per GB/T10561
3.Tolerance of outer diameter±0 .75(%), tolerance of wall thickness +22.5／0(%)- +15／0(%), straightness over whole length <0.15%, surface roughness Ra3.2-0.8, maximum length 16500mm;
4. Other technical specifications are implemented according to GB18248-2008.