Valco GC valves have been in almost all commercially-produced gas chromatographs from the time that valves originally began to replace other injection methods. New designs are smaller and easier to service, but still exhibit the quality and value that made them the industry standard.
Medium temperature GC valves have a rotor made of Valco E, a polyaryletherketone/PTFE composite. High temperature GC valves use a polyimide/PTFE/carbon composite designated Valcon T.