welded steel pipe HFW/ERW /SSAW/SAW /SMAW Quality GB/T 9711 3091 Material Q195-235B Product Type: ERW Steel PipeProcess Method: ERW, HFI, EFWQuality Standard API 5L, A53, GB/ T 3091Steel Grade Gr. A, B, C, Q195, Q235, Q345Dimension " a) OD: 42-610mmb) WT: 5-30mm"" c) NPS: 1-1/ 2" " -24" "d) Schedule: sch20, sch30, sch40, sch80, XS, STD"Length: Random or Fix 5.8-12 meterSurface Finish: Oiled or ...