Product Overview
The KDG4V series is a non-feedback proportional directional control valve from Eaton Vickers (now Danfoss Power Solutions), part of the standard performance product line. The KDG4V-5-2C50N-Z-M-U1-H7-30 is a D05 (NG10) size, C-type dual-solenoid proportional directional valve with a 33-type spool configuration—P port closed, A and B ports exhausting to T.
The valve proportionally controls spool displacement in response to solenoid current, enabling integrated control of flow, direction, acceleration, and deceleration of hydraulic actuators. As a non-feedback proportional valve, it bridges the performance gap between conventional solenoid directional valves and servo valves, offering a cost-effective solution for applications where ultra-high precision and fast response are not critical.
As a direct OEM-replacement solution, this valve maintains 100% mechanical and functional interchangeability with the original Eaton Vickers unit. Every valve undergoes rigorous simulation testing—including pressure cycling, thermal variation, and full-stroke endurance validation—to guarantee factory-grade performance.
Technical Specifications
KDG4V-5-2C50N-Z-M-U1-H7-30:
Model: KDG4V-5-2C50N-Z-M-U1-H7-30
Brand: Eaton Vickers (Danfoss Power Solutions)
Valve Type: Proportional directional control valve, non-feedback
Size: D05 NFPA / NG10
Mounting Interface: ISO 4401-05
Mounting Type: Subplate mounted
Spring Arrangement: C-type (dual solenoid, spring-centered)
Spool Type: Type 33 (P closed, A & B to T)
Rated Flow: 50 L/min (13.2 USGPM) with metered inlet and metered return
Max. Operating Pressure: 350 bar (5000 psi)
Tank Port Rating: 210 bar
Pressure Drop at Rated Flow: 145
Coil Voltage: 24V DC
Electrical Connection: ISO 4400 / DIN 43650 connector
Control Type: Solenoid operated
Manual Override: None (Z-type)
Seal Material: Fluorocarbon
Body Material: Gray iron
Feedback Sensor: None
Recommended Fluid Cleanliness: ISO 4406 17/15/12
Operating Temperature Range: -4°F to 179.6°F (-20°C to 82°C)
Weight: 13.8 lb (approx. 6.26 kg)
Design Series: 30 Series
Key Technical Advantages
1. Integrated Flow and Direction Control – Simplified System Design
KDG4V series valves integrate flow, direction, acceleration, and deceleration control within a single valve body. This integrated design significantly simplifies hydraulic circuit layouts, reduces external component counts, and minimizes system complexity and potential failure points.
2. Cost-Effective Proportional Control Solution
As a non-feedback proportional valve, the KDG4V series fills the performance gap between conventional solenoid directional valves and servo valves. It offers a more cost-effective control solution than servo valves and feedback-type proportional valves for applications that do not demand ultra-high precision, repeatability, or fast response.
3. Proven Fatigue Life and Long-Term Reliability
All KDG4V series valves are rated for NFPA fatigue at 350 bar (5075 psi). The field-proven fatigue life and enduring reliability ensure high machine productivity and extended service life.
4. Common Component Design – Easy Maintenance
KDG4V valves share common components with Vickers DG4V-3(S) solenoid directional valves, significantly reducing installation and spare parts costs. The fully encapsulated solenoids are impervious to common industrial fluids, and solenoid coils can be easily removed and replaced without compromising the hydraulic system’s integrity.
5. Drop-In Interchangeability – Minimized Downtime and Retrofit Costs
The valve strictly adheres to Eaton Vickers’ original mounting dimensions and functional specifications, with ISO 4401-05 interface compliance. Whether for new system design or legacy system upgrades, this valve offers 100% mechanical and electrical interchangeability with the original Eaton Vickers unit—eliminating the need for manifold modifications or piping changes, significantly reducing downtime and retrofit expenses.
Application Areas
Agricultural Machinery – Widely used in automatic steering systems for New Holland and other AG equipment
Injection Molding Equipment – Proportional control of injection speed and direction
Machine Tool Hydraulic Systems – Proportional control of table feed speed and direction
Material Handling Equipment – Direction and speed control for forklifts and lifting platforms
Packaging Machinery – Smooth acceleration and deceleration control of actuators
Industrial Automation Lines – Proportional flow and direction regulation for hydraulic actuators
Expert Maintenance Tips
1. Fluid Cleanliness Management
KDG4V series proportional valves require a recommended fluid cleanliness level of ISO 4406 17/15/12. Install filters with a minimum rating of 10μm upstream of the valve and regularly monitor fluid contamination levels to prevent spool sticking or wear.
2. Initial Start-Up Air Bleeding
Air must be bled from the proportional solenoids during initial start-up: remove the bleed screws until no bubbles appear, then reinstall the bleed screws. Alternatively, remove both bleed screws and use a standard oil can nozzle to pump fluid into one side until it flows out the other.
3. Electrical Connections and Signal Matching
The valve operates on 24V DC coil voltagewith ISO 4400 / DIN 43650 electrical connections. Verify that the supply voltage matches the valve’s electrical specifications prior to installation. Use shielded cables for control signal transmission with reliable single-point grounding to effectively suppress electromagnetic interference.
4. Installation and Sealing
The valve utilizes a standard NFPA/ISO subplate or manifold mounting interface. Ensure the mounting surface is flat and smooth, and tighten mounting bolts evenly to specified torque. Properly install seals without damage or omission. Tank port backpressure must not exceed the 210 bar rating.
5. Periodic Inspection and Maintenance
Regularly verify the valve’s flow-current characteristic curve. If abnormal response or increased hysteresis is detected, inspect the solenoid condition and pilot oil circuit for obstructions. For systems that have been idle for extended periods, perform thorough system circulation filtration before restart to ensure fluid cleanliness meets requirements.
