Vickers KFDG4V Proportional Valve | KFDG4V-3-33C13N-Z-M-U1-H7-20 | OBE Solenoid Valve

The KFDG4V-3 Series proportional solenoid valves from Chengyuan Hydraulic are high-performance, direct-operated valves fully compatible with Vickers industrial standards. This series features integrated On-Board Electronics (OBE), allowing direct control of hydraulic flow and direction via +/- 10V or 4-20mA signals. For core models such as KFDG4V-3-33C13N and 33C20N, we implement high-precision LVDT displacement sensors for closed-loop spool position feedback. Every proportional valve undergoes 100% dynamic response testing to verify that linearity and frequency response under 350 bar pressure match original OEM standards, ensuring 100% original-place interchangeability.

Technical Specifications :

• Nominal Size: NG06 / CETOP 03 / ISO 4401-03

• Control Type: Integrated OBE (On-Board Electronics)

• Spool Function: 33C (Closed center, proportional control)

• Rated Flow (at Δp=10 bar): 07 (7 L/min), 13 (13 L/min), 20 (20 L/min)

• Max Operating Pressure (P, A, B Ports): 315 – 350 bar

• Max Tank Pressure (T Port): 210 bar

• Feedback System: Z (LVDT spool position feedback)

• Control Signal: U1 (+/- 10V voltage signal) / Current options available

• Electrical Connection: H7 (7-pin standard connector)

• Seal Material: N (Nitrile) / VM (Viton for high-temperature/synthetic fluids)

Key Technical Advantages:

• Integrated OBE Technology: The core of the KFDG4V series is its built-in high-speed electronic controller. Users eliminate the need for external amplifier cards in control cabinets. Chengyuan’s OBE system is optimized for electromagnetic compatibility (EMC) to resist heavy industrial electrical interference.

• Precision LVDT Closed-Loop Control: The Z-type LVDT sensor monitors spool travel in real-time, automatically correcting errors caused by pressure fluctuations or fluid viscosity changes. This results in exceptionally low hysteresis (< 0.5%) and superior repeatability.

• Precision-Ground Proportional Spools: The spool is crafted from specialized alloy steel with intricate metering notches. This manufacturing precision ensures excellent flow linearity across the entire control range, eliminating directional switching shocks.

• 100% Dynamic Validation: Proportional valves require high response speeds. Chengyuan performs step-response tests on every KFDG4V valve to ensure frequency response meets the demanding requirements of injection molding, metallurgy, and test rigs.

Application Areas:

• Precision Machine Tools: Synchronized control for CNC press brakes and feed drives for machining centers.

• Plastics Machinery: Precise proportional adjustment for injection pressure and mold movements.

• Test Rigs & Simulators: Hydraulic experimental benches requiring high-frequency switching and accurate flow control.

Expert Maintenance Tips:

• Strict Filtration Standards: Proportional valves are highly sensitive to contaminants. Use filtration rated at 3μm or better to maintain oil cleanliness at NAS 1638 Grade 7 (ISO 4406 16/14/11).

• Electrical Shielding & Grounding: Always use shielded 7-pin cables and ensure the aviation plug is properly grounded to prevent stray signals from compromising control accuracy.

• Zero-Point Adjustment: If the system exhibits slight creeping at zero signal, the zero-point potentiometer under the OBE cover can be micro-adjusted (recommended under professional guidance).