... certificate. High exporting quality and competitive price high pressure API slip on alloy steel flange (SO)Size: from 1/2to ... colored electroplate, powder coating and so on. Varieties: threaded flange, slip-on flange (SO), socket welding flange, lap joint flange ( ... neck flange (WNF), blind flange, orifice flange, reducing flange, pad type flange, loose hubbed flange, welding plate flange, welding neck ...