Hydraulic Solenoid Valves

Hydraulic solenoid valves are electrically actuated directional control valves for controlling hydraulic fluid flow. A coil (e.g. 12 V, 24 V or 220 V) generates a magnetic field that actuates the valve mechanism – usually a movable spool or plunger. This opens/closes channels and directs the oil flow, enabling precise electrical control of cylinders and motors.

• Line-mounted valves: Integrated directly into pipelines, with threaded connections.
• Subplate-mounted valves (e.g. CETOP valves): Mounted on subplates/manifolds, standardized porting patterns (ISO 4401), space-saving; often solenoid operated.
• Sandwich plate valves: Installed between base plate and stack valve, controlling hydraulic flow.
• Monoblock valves: A cast block with multiple valve cavities; fewer sealing surfaces, but in case of failure the entire block must be replaced.
• Cartridge valves: Screwed directly into a cavity of a manifold/housing, very space-saving.
• Modular stack valves: Combinable functional/valve plates for compact, flexible assemblies.

• Agricultural machinery (e.g. tractors)
• Construction machinery (e.g. excavators)
• Municipal machinery (e.g. refuse trucks)
• General industrial equipment (e.g. presses, production lines, injection molding machines)
• Machine controls
• Transport and agricultural equipment
• Elevators
• Medical technology
• Industrial automation systems

They control cylinder movements and motors, regulate start, stop and directional changes of hydraulic actuators.

• Electrical controllability: Fast, precise, remotely controllable operation – manual or automated.
• Versatility: Wide range of designs, circuit functions and voltages (12 V, 24 V, 220 V).
• Durability: Robust materials and coils for frequent switching cycles and high pressures.
• Wide application range: Versions for virtually every pressure and flow range.

• Size & port pattern: Depending on required flow capacity and pressure rating.
• Flow & maximum operating pressure: Valve must reliably cover system peaks.
• Coil voltage: Common options 12 V, 24 V, 220 V.
• Function & valve type: Direct operated, proportional, sandwich design; required spool/circuit function (e.g. 4/2-, 4/3-way).
• Fluid compatibility: Materials and seals chemically compatible with the hydraulic medium.

For the perfect selection, qualified technical consultation is recommended.

Hydraulic valves are key control and regulating elements – without them, almost nothing works. They perform, among others:

• Starting and stopping movements
• Changing the direction of actuators (e.g. cylinders, motors)
• Adjusting/limiting pressure
• Regulating flow
• Holding loads or actuating pilot lines

Regular maintenance (typically every 6–12 months) increases reliability and service life:

• Visual inspections: Check coil and electrical contacts for defects/corrosion.
• Cleaning: Occasionally clean valve ports and connectors.
• Resistance measurement: Check condition of the solenoid coil.
• Clean contacts: Ensure corrosion-free, secure plug connections.

With correct design, clean power supply and regular servicing, solenoid valves often achieve several million switching cycles; actual values depend on load profile, operating conditions and maintenance intervals.