Pipe Flange Standard Systems

There are two primary international systems for pipe flange standards: the European system, represented by German DIN standards (including those of the former Soviet Union), and the American system, represented by ANSI standards. Additionally, there is the Japanese JIS standard; however, in petrochemical facilities, it is generally used only for utility systems and has limited international influence. Brief descriptions of the pipe flange standards from various countries follow:
1. European system pipe flanges, represented by Germany and the former Soviet Union.
2. American system pipe flanges, represented by ANSI B16.5 and ANSI B16.47.
3. British and French pipe flange standards; each of these countries maintains two sets of standards.
In summary, internationally recognized pipe flange standards can be categorized into two distinct and mutually incompatible systems: the European system (represented by Germany) and the American system (represented by the United States).
ISO 7005-1 is a standard issued by the International Organization for Standardization in 1992; it effectively merges the American and German pipe flange standard series into a single unified standard.