Glossary · Pneumatics and hydraulics
Solenoid valve
Also known as: Electrically operated valve, Magnetic valve
German: Magnetventil
In fluid power and process automation, a solenoid valve is a valve actuated by an electromagnet (solenoid), either directly or through a pilot stage, to switch the flow of a gas or liquid on, off or between ports in response to an electrical signal.
- Fluid power
In one sentence
A solenoid valve uses an electromagnet, directly or via a pilot, to switch fluid flow in response to an electrical signal.
Example
A 24 V DC solenoid valve on the valve island extends the ejector cylinder when the PLC sets the output.
How it applies
- Engineering: Monostable (spring return) and bistable (two solenoids, memory) valves behave differently on power loss: monostable valves return, bistable ones keep their position. Pilot-operated valves need a minimum pressure.
- Commissioning: Solenoid wiring and addressing are checked against the circuit and electrical diagrams; manual overrides are tested and then secured.
- Operation: Coil failure or loss of voltage returns monostable valves to their rest position.
- Documentation: State for each valve whether it is monostable or bistable and the resulting actuator behavior on power loss and return. Warn that manual overrides move actuators even when the control is off.
Solenoid valve vs. proportional valve
A solenoid valve switches between discrete positions. A Proportional valve varies its opening continuously with the signal.