Stainless steel 4H Blind Flanges 1.ASTM A105 and ANSI B16.5. 2.Size: 1/2" to 24" 3.stainless steel SS304 or 316 Lianfa stainless steel pipes and valves(qingyun) co.,ltd specilizes in manufacturing stainless steel pipe fittings, ball valves,sanitary fittings and valves,quick coupling,flexible fittings,flanges and carbon steel valves.