| Solenoid-Operated Directional Valve | Switches hydraulic flow between ports or positions. | 24 VDC or 110/230 VAC On/off command | Up to approximately 315 bar | Approximately 5–120 L/min | Typical switching time: 20–60 ms Limited intermediate-position control | Discrete flow paths; flow is mainly determined by spool size and pressure drop. | General machinery, clamping, lifts, machine tools, and basic automation | Confirm spool configuration, allowable pressure drop, switching frequency, and coil voltage. |
| Electro-Hydraulic Proportional Directional Valve | Continuously controls actuator direction and speed. | 0–10 V ±10 V 4–20 mA | Approximately 210–315 bar | Approximately 10–1,000 L/min, depending on nominal size | Typical response: 20–100 ms Moderate positioning accuracy | Variable spool opening regulates flow; actuator speed changes with command input. | Mobile equipment, injection machinery, presses, material handling, and automation | Check command electronics, spool overlap, hysteresis, contamination rating, and required flow capacity. |
| Servo-Proportional Directional Valve | Provides high-accuracy closed-loop control of position, velocity, or force. | ±10 V Digital fieldbus or motion-controller command | Approximately 210–350 bar | Approximately 50–1,000 L/min | Typical response: 3–20 ms Very low hysteresis when correctly tuned | Fine spool metering supports rapid, repeatable control of flow direction and magnitude. | Test systems, metal forming, plastics machinery, precision presses, and flight or motion simulators | Requires clean hydraulic fluid, suitable feedback control, stable electronics, and careful commissioning. |
| Electro-Proportional Pressure-Relief Valve | Limits or adjusts maximum system pressure electronically. | 0–10 V 4–20 mA PWM input on some configurations | Approximately 50–350 bar | Approximately 5–300 L/min, depending on valve size | Typical response: 20–100 ms Pressure accuracy commonly within a few percent of full scale | Changes the pressure setting continuously while diverting excess flow when the limit is reached. | Variable-load systems, presses, mobile hydraulics, and energy-saving power units | Match pressure range to the required setpoint; verify minimum flow, pilot requirements, and heat generation. |
| Electro-Proportional Pressure-Reducing Valve | Maintains a controlled downstream pressure below inlet pressure. | 0–10 V 4–20 mA | Inlet: approximately 210–315 bar Outlet setting: approximately 5–250 bar | Approximately 5–100 L/min | Typical response: 30–120 ms Accuracy depends on load, temperature, and feedback | Regulates pressure in a secondary circuit independently of the main supply pressure. | Clamping, braking, pilot circuits, tooling, and multi-pressure hydraulic systems | Consider minimum pressure differential, leakage, downstream flow demand, and pressure stability. |
| Electro-Proportional Flow-Control Valve | Adjusts hydraulic flow to control actuator speed. | 0–10 V 4–20 mA PWM input on some models | Approximately 210–350 bar | Approximately 0.5–500 L/min | Typical response: 20–100 ms Flow accuracy is affected by pressure compensation and load changes | Meter-in, meter-out, or pressure-compensated metering controls flow independently or partially independently of load. | Actuator speed control, conveyors, winches, agricultural machinery, and process equipment | Choose pressure-compensated designs when load pressure varies significantly. |
| Electro-Hydraulic Pressure-Compensated Flow Valve | Maintains commanded flow despite moderate load-pressure changes. | 0–10 V 4–20 mA | Approximately 210–350 bar | Approximately 1–300 L/min | Typical response: 30–120 ms Better speed consistency than a simple throttle valve | An internal compensator maintains a relatively stable pressure drop across the metering orifice. | Mobile hydraulic functions, lifting systems, feed mechanisms, and synchronized actuators | Check compensator operating range, minimum pressure drop, and maximum allowable leakage. |
| Electro-Hydraulic Poppet or Cartridge Valve | Controls high flow through a compact two-way or multi-function cartridge element. | Solenoid on/off or proportional pilot control | Approximately 250–420 bar | Approximately 50–2,000 L/min | Fast switching for on/off versions; proportional versions typically respond in 20–100 ms | Large flow capacity with low pressure loss; can provide tight shutoff when correctly selected. | Presses, injection machines, hydraulic power units, high-flow manifolds, and mobile machinery | Evaluate cavity standard, pilot ratio, installation orientation, leakage class, and service access. |
| Electro-Hydraulic Check Valve | Allows free flow in one direction and blocks or releases reverse flow electrically. | Solenoid on/off or pilot-control signal | Approximately 210–420 bar | Approximately 5–1,000 L/min | Fast load-holding action; response depends on pilot volume and spring selection | Provides load holding, controlled release, and protection against reverse actuator movement. | Hoists, cylinders, presses, platforms, and safety-related load-holding circuits | Verify cracking pressure, pilot ratio, leakage requirement, shock loads, and emergency-release behavior. |
| Electro-Hydraulic Servo Pressure or Flow Valve | Uses electronic feedback to regulate pressure or flow with high dynamic accuracy. | ±10 V Digital controller or fieldbus command | Approximately 100–350 bar | Approximately 5–500 L/min | Fast closed-loop response; high repeatability when paired with pressure or flow sensors | Continuously corrects the valve command using measured hydraulic feedback. | Precision test rigs, forming equipment, closed-loop force control, and high-performance automation | Budget for sensors, controller tuning, fluid cleanliness, filtration, and system-level commissioning. |