For fluid valves there are a number of actuation types:
- Manual actuation: Actuation using a hand or foot (including manual override).
- Mechanical actuation using levers, plungers and/or rollers and springs.
- Electrical actuation using electromagnets with a single or double effect or electric motors.
This also includes proportional solenoids and electro-mechanicalsignal converters for single stage servo valves.
- Pressure actuation by hydraulic or pneumatic pressurisation or pressure release.
- Combined electro-hydraulic or electro-pneumatic actuation: A main valve is hydraulically or pneumatically switched by an electrically actuated pilot valve. The terms pilot-controlled valves and Pilot-operated valves are used.