carbon steel flange ISO Ctification Standards:ANSI,DIN,JIS,GB,BS special design available size:10~6000mm carbon steel square flangeSTANDARDS:. ... .SP 44,JIS B2220,DIN AND BS NORMS. ASME, ANSI, API, JIS, JPI, DIN, UNI, BS, AS.JIS Weld NeckProduction size(NPS ...