large diameter welded spiral pipe 1. Grade: Q345B, API X42 - X80, L245, L555, J55, N80 2. Standard: SY/T5037-2000, GB/T Large diameter ... paper, PVC sleeve, and sackcloth with several steel strips, Plastic caps or according to your requirement7. Inspection: Chemical Component ... mainly used for oil, natural gas, gas, central heating, water supply, sewage treatment, low-pressure fluid delivery and so on ...