Welded Spiral Steel Pipe 1.grade:Q235,Q345,10#,20#,16Mn,L245,X80 ... GB/T 3.OD:219-3000mm thickness:6-25mm Welded Spiral Steel Pipe1. Material:Q235,Q345,10#,20#,16Mn,L245,L290 ... request5. Application: For linepipe in petroleum and natural gas , water and gas, mineral slurry. Also for chemical industry, building structure ... my name is Tina, your inquiries will be highly appreciated! Welded Spiral Steel Pipe