Schematics of ISO and Japanese Standards on Flange Sealing Systems and Fittings for Vacuum Equipments, and Their Correlations

To keep flexibility on construction of vacuum system, understanding of standardization scheme for demountable sealing system consisting of flanges and metal gasket or elastomer O-ring is highly beneficial for both suppliers and users of vacuum equipments. Here we present main contents of international and national standards of flange sealing systems and their correlation, along with some commentaries on states of conformity with standards of commercially available vacuum flanges. Outlines of standards of vacuum fittings, and recent activities for revision and establishment of standards are also reported.