The international standard of pipe Flanges has two systems, namely, the German DIN (including the former Soviet Union) as the representative of the European pipe flange system and the United States ANSI Pipe flange as the representative of the American pipe system. In addition, Japan JIS pipe flange, but in the petrochemical plant is generally used only for public works, and in the international impact of the small, now the introduction of various countries pipe flanges:
1, the European System pipe flanges represented by Germany and the former Soviet Union
2, the American system flange standard, with ANSI B16.5 and ANSI B 16.47 as the representative
3, the British and French pipe flange standards, each with two casing flange standard.
To sum up, the international common pipe flange standard can be summed up as two different, and can not be interchangeable pipe flange system: A German-represented European pipe flange system.