The ASCO Series 210 Direct Operated Hung Diaphragm Vacuum Valves are designed for high vacuum applications, where molecular contamination is a concern. To avoid such contamination, the valves are made from special materials and undergo specific handling procedures. Additionally, the medium and high vacuum valves undergo mass spectrometer testing to ensure they meet the highest standards. The valves are two-way shut-off pilot-operated valves that are compatible with air and inert gas and are designed to meet all relevant EC Directives.