... 3.Type: Welding neck(WN) , Slip-on(SO) , Threaded(TH) , Socket-welding(SW) , Blind(BL) , Orifice flange (OF),or by customers ... ) , Alloy Steel(AS)5.Standard: ANSI,ASTM,API,UNI,JIS,BS,DIN,EN,GB.6. Size: 3/8 "-- 60", 1/2 ... by Alibaba.com15. Loading port: Dalian port JIS ANSI DIN BS Blind Flange