... ,HK40,steel 3.ISO9001:2008 Weld Neck Slip on Lap Joint Flange Varieties: threaded flange, slip-on flange (SO), ... socket welding flange, lap joint flange (LJF), welding neck flange (WNF), blind flange, orifice flange ... : rust preventing oil, spray paint (black, yellow), hot galvanization, cold galvanization or colored electroplate, powder coating and so on. Detailed ...