Oil Line Pipes 1.Standard:BS, GB, DIN, ASTM, API 2.Grade:20#, ... , St52, St42, Q.. 3.Outer Diameter:8-24mm Oil Line Pipes Spiral Seam double-side submerged arc welded steel pipe1. Standard ... . Oil tube 7. hot-galvanized steel pipe Ssaw Oil Line Pipes (L415, L320, L450)