... Carbon Steel 2,Standard:ASME, DIN, BS, JIS, JB, GB, 3,Cert:TUV,ISO9001:2000,NK,BV DIN 2533 flangesize 1 ... B16.5, ASME B16.47, ASME B16.36,DIN 86341-2000, DIN2505material Carbon steel(ASTM A105, Q235, ... National Petroleum Corporation.We are also qualified the standard material supplier of China National Offshore Oil Corporation ... etcSpecial design available as the requirement of customer DIN 2533 flange