... ,GB,ISO material:API 5L, A53,A106,A333 GR6,Q235,Q345 API tube SSAW (Spiral Submerged-arc Welded) Quality standard: API 5L Gas and petroleum ... , St13, St14, St33,St37, St44, ST52ASTM A 53: Gr. A, Gr B, Gr C, Gr.DAPI 5L: A, B, X42, X46, X52, X56, X60, X65 X70GB/T9711 ... joint: The special manufactured flanged are welded to the ends of the pipe and then jointed with bolts. Test:Chemical Component Analysis ...