... of special flanges.Standard:America:ASME B16.5,ASME B16.48,ASME B16.47,API 590China:GB/T9112~GB/T9124-2000 ... ,S31803(2205),S32304,S32205,S32760,S32750,HDRCopper Nickel Alloy:B10,B30Special steel:N06600,N08800,N08811,Titanium alloy, Alloy steel etc.Carbon manganese steel:20 ...