... welding neck, blind and so on. ANSI B16.5 Ring Joint Facing flange class150-2500Sizes: DN15 to DN1200, 1/2 inch ... EN1092,UNI,GOST12820-80Types: plate, slip on, welding neck, blind, thread, socket weld flangeProcess: free forging, plate cutting, heat treat, machiningSurface ... forging, machining, assembly, inspection, packaging productionPaul JingSales manager Ring Joint Facing flange class150-2500