Vickers KCG Series Proportional Relief Valve | KCG-3 KCG-6 | Hydraulic Pressure Control

Chengyuan Hydraulic offers high-performance KCG Series proportional solenoid relief valves, meticulously engineered to replace Vickers advanced pressure control standards. This series (including models KCG-3-L250D and KCG-6-W100) features a pilot-operated design, enabling remote and precise stepless regulation of hydraulic system pressure via input current adjustment. In modern automated hydraulic systems, Chengyuan ensures 100% Drop-in Interchangeability regarding mounting interface dimensions (ISO 4401-03/05), electrical connector definitions, and flow characteristics. Backed by our 100% Simulation Load Testing, each KCG valve undergoes pressure-ramp linearity verification before shipment, guaranteeing exceptional stability and repeatability during dynamic pressure transitions.

Technical Specifications 

• Series Category: KCG-3 (NG6 / ISO 4401-03) / KCG-6 (NG10 / ISO 4401-05)

• Max Operating Pressure (Port P): 250 bar (25 MPa) / 315 bar (depending on code)

• Pressure Adjustment Ranges: 4-100 bar / 7-160 bar / 10-250 bar (Codes L100, L160, L250)

• Rated Flow (KCG-3): 5 L/min (Pilot stage control)

• Rated Flow (KCG-6): Up to 40 L/min (Application dependent)

• Solenoid Voltage: 12V DC / 24V DC

• Coil Resistance: 4.8 Ω (for 24V specs)

• Hysteresis: < 3% (with optimized amplifier)

• Repeatability: < 1%

Key Technical Advantages:

• Precision Linear Solenoid: The internal electromagnetic actuator utilizes optimized magnetic alloys, ensuring a strict linear relationship between thrust and input current, which significantly enhances system control accuracy.

• Pilot-Operated Smooth Discharge: Features an optimized pilot poppet assembly that effectively dampens pressure surges during proportional regulation. This maintains low noise and vibration levels even under high-pressure, high-flow switching.

• High Dynamic Response: Spools are precision-ground and treated to minimize stiction, allowing for microsecond response times that meet the demands of rapid pressure compensation in closed-loop systems.

• Anti-Contamination Flow Path: The integrated orifices in the KCG-3/6 series are designed for clogging resistance. Combined with high-strength cast steel bodies, these valves maintain long-term stability in demanding industrial environments.

Application Areas:

• Injection Molding: Multi-stage proportional control of clamping force and injection pressure.

• Die-Casting Equipment: Precise pressure curve regulation during the molten metal extrusion process.

• Metalworking Tools: Proportional unloading and safety pressure monitoring in presses and shears.

• General Hydraulic Units: Acting as the pilot unit for main control blocks to enable flexible pressure switching.

Expert Maintenance Tips:

• Amplifier Compatibility: To achieve peak linearity and minimum hysteresis, it is highly recommended to use a dedicated proportional controller with a superimposed dither signal.

• Filtration Standards: Proportional valves are sensitive to particulates. Maintain a filtration accuracy finer than 10μm and an oil cleanliness level of NAS Class 8 or better to prevent pilot spool sticking.

• Air Bleeding: During initial startup, loosen the bleed screw on top of the valve to purge air from the solenoid chamber, ensuring maximum sensitivity in pressure regulation.