... , ASTM A350 LF1, LF2 CL1/CL2, Item name:Socket Welding Flange(welding flange,flanges factory )Material:Carbon SteelASTM A105, ASTM A350 LF1, LF2 ... :ASTM A182 F1, F5a, F9, F11, F12, F22, F91 Socket Welding Flange(welding flange,flanges factory )