CS GOST RUSSIAN STANDARD FLANGE standard:gost size:1/2"-24" pressure: pn6.pn10,pn16,pn25,pn40, ... ON ,BLIND ,PLATE,THREADED,LAPPED ,SCREWDE,SOCKET WELDING pressure :PN 6,PN 16,PN 10,PN 25,PN40,PN63materail:CS CT20,16Mn ... ,GALVANIZED ,BLACK. PACKAGE:PLYWOODEN CASE PACKAGE,,WOOD PALLET PACKAGE Remark:GOST 12820:PLATE FLANGEGOST BLIND FLANGEGOST 12821 :WELDING NECK FLANGE