Vacuum technology puts great demands on the functioning and reliability of the valves. The demands are fulfilled only if correct shut-off devices are installed for each application, depending on the method of construction, method of operation, and size. Moreover, in the construction and operation of vacuum plants, factors such as the flow conductance and leak-tightness of valves are of great importance. The valves of Leybold are optimized with regard to these demands. For every flange system there are a lot of valve types available.