GB6479 steel pipe is a high-pressure seamless steel pipe for chemical fertilizer equipment (GB6479-2000) is a high-quality carbon structural steel and alloy steel seamless steel pipe suitable for chemical equipment and pipelines with a working temperature of -40~400°C and a working pressure of 10~30Ma .

Hot rolling (extruded seamless steel pipe): round tube billet → heating → piercing → three-roll cross rolling, continuous rolling or extrusion → tube removal → sizing (or reducing) → cooling → billet tube → straightening → quality inspection Wall thickness→hydraulic test (or flaw detection)→marking→storage.
Cold drawn (rolled) seamless steel pipe: round tube blank→heating→perforation→heading→annealing→pickling→oiling (copper plating)→multi-pass cold drawing (cold rolling)→blank tube→heat treatment→straightening→ Quality inspection wall thickness→hydraulic test (flaw detection)→marking→storage.