Valves with a large nominal width (generally greater than the nominal size 16 or sometimes at nominal size 10 or nominal size 6) and therefore with large actuation forces are pilot-controlled by a smaller valve (pilot valve). Here the pilot valve can be mechanically actuated (e.g. for piloted check valves), pressure actuated (e.g. for pressure valves) or electrically actuated (e.g. directional valves) (cf. Indirect actuation). Pilot-controlled valves are also called multi-stage valves.
Alternative: Directly actuated valves.