... ASME B16.36,DIN2505,EtcMaterialCarbon steel(ASTM A105,Q235,A350LF2,A350LF3,Etc)Stainless steel(ASTM A182 F304, F304L ... ,F316,F316L,F321,F347,F310F44F51,A276 S31803, A182, F43,Etc)Alloy steel ... .We are also qualified the standard material supplier of China National Offshore Oil Corporation and ... FlangeWelding Neck Flange ISO certificate stainless steel flange (supplier)