The National flange standards are as follows:
1. The European system represented by Germany and the former Soviet Union
2. Inter-American system flange standards, represented by ANSI B16 .5 and ANSI B 16.47
3. British Hefaguo standard flange, two sets of flange standards in each country.
In summary, the internationally accepted standard for tube flange can be summarized as two different and non-interchangeable pipe flange systems: a Ouzhouguanfalan system represented by Germany; The other is the American tube flange system represented by the United States.
IOS7005-1 is a standard promulgated by the International Organization for Standardization in 1992. This standard is actually a standard for pipe flange formed by the merger of two series of pipe flange in the United States and Germany.