Vickers KBFDG4V-3 Proportional Valve | KBFDG4V-3-2C20N 2C13N 2C07N

The KBFDG4V-3 Series of direct-operated electro-hydraulic proportional directional control valves manufactured by Chengyuan Hydraulic are flagship fluid power elements engineered to fully match the premier industry benchmarks of Eaton Vickers. This high-tier proportional platform is optimized for closed-loop automation grids requiring simultaneous, highly accurate regulation of hydraulic fluid velocity, volumetric flow rate, and directional tracking. Focusing on the targeted performance catalog codes provided—KBFDG4V-3-2C20N-Z-M1-PC7 H7 (20 L/min maximum profile), KBFDG4V-3-2C13N-Z-M1-PE7-H7, and KBFDG4V-3-2C07N-Z-M1-PE7-H7 (precision low-flow matrix)—Chengyuan applies sub-micron lapping assembly paired with advanced On-Board Electronics (OBE) to guarantee 100% original-place interchangeable plug-and-play compatibility. Every single valve is subjected to 100% simulated loaded condition testing, dynamic frequency mapping, dead-band thresholding, and hysteresis validation before dispatch, securing stable command tracing under aggressive 315 bar system pressure profiles.

Technical Specifications 

• Brand Cross-Reference: Eaton Vickers KBFDG4V-3 Compatible Matrix

• Target Model Nomenclature: KBFDG4V-3-2C20N-Z-M1-PC7 H7, KBFDG4V-3-2C13N-Z-M1-PE7-H7, KBFDG4V-3-2C07N-Z-M1-PE7-H7

• Mounting Configuration standard: CETOP 3 / ISO 4401-03 (Nominal Size NG6 subplate interface)

• Spool Function Matrix: 2C (4-way, 3-position, center-closed standard configuration, spring-centered dual solenoid drive)

• Nominal Rated Flow Class ($\Delta p = 5$ bar per metering edge):

  • 2C07N: 7 L/min (High-resolution precision flow profile)

  • 2C13N: 13 L/min (Medium-capacity flow profile)

  • 2C20N: 20 L/min (Full-capacity flow profile)

• Maximum System Pressure Rating (Ports A, B, P): 315 bar (4568 psi)

• Maximum Allowable Backpressure (Port T): 210 bar (3045 psi max rating)

• Electronic Command Format Interfaces (PC7 / PE7):

  • PC7: Voltage instruction signal variant ($\pm 10V$ DC differential input range)

  • PE7: Current instruction signal variant (4-20 mA or $\pm 20mA$ constant current loop standard)

• Electrical Connection Interface (M1): Standard 7-pin heavy-duty integrated electrical socket configuration

• Power Supply Requirement: 24V DC nominal (Acceptable span: 21V – 28V) with integrated reverse polarity protection

Key Technical Advantages:

• Integrated Fully Calibrated On-Board Electronics (OBE): The KBFDG4V-3 platform houses a ruggedized digital proportional amplifier block seamlessly mounted to the valve enclosure. Mechanical spool center calibration, dead-band compensation tuning, and maximum gain controls are pre-set digitally via Chengyuan testing benches prior to delivery. Operating technicians only need to pipe in 24V power and differential inputs via the 7-pin socket, skipping cabinet layout heating problems while yielding immunity against localized electromagnetic interference (EMI).

• Sub-Micron Lapped Spool-to-Bore Assembly: The core sliding spool is machined from advanced wear-resistant tool steel cores, hardened and micro-ground to maintain a strict 2-micron single-side clearance gap within the ductile iron enclosure. Precise spool land overlap profiling coupled with computerized laser-cut metering notches guarantees extremely smooth, predictable flow gain plots down to a minimal 5% command step input.

• Closed-Loop Spool Positioning via High-Resolution LVDT: A highly responsive linear variable differential transformer (LVDT) sensor monitors real-time spool positioning on the longitudinal axis. The OBE controller continuously processes this feedback loop to offset unintended spool displacement caused by fluid flow-forces or fluid viscosity fluctuations, compressing the total valve hysteresis to $\le 0.5\%$.

• Heavy-Duty High-Response Proportional Solenoid Blocks: Proportional coil windings are encapsulated in heavy-duty impact-resistant polymers mated to pressure-resistant armature tubes. This robust design enables the T-port to accept intense continuous return-line shock backpressures up to 210 bar without triggering internal hydraulic sticking during rapid multi-axis reversals.

Application Areas:

• High-Accuracy CNC Machine Tools: Multi-axis synchronous cylinder tracking, automated pipe bending equipment velocity ramping profiles.

• Heavy Metallurgy & Plastic Injection Manifolds: Core pull and die clamping circuits for heavy foundry systems, cold/hot-rolling mill gap adjustment block assemblies.

• Industrial Simulation & Dynamic Test Benches: Actuator propulsion blocks for multi-axis aerodynamic shaker tables and component stress validation rigs.

Expert Maintenance Tips:

• Enforce Uncompromising ISO 4406 Cleanliness Auditing: Due to its micron-level tolerances and electronic feedback architecture, this valve is sensitive to micro-particulates (such as metal shavings, dust silt, or localized fluid oxidation scales). The pressure circuit must be fitted with premium glass-fiber inline filtration featuring an absolute rating of 5 microns ($\beta_5 \ge 200$). Maintain fluid cleanliness at ISO 4406 17/15/12 or better to prevent spool land scoring and orifice clogging.

• Strictly Prohibit Live Hot-Plugging of the 7-Pin Electrical Harness: The integrated digital card components contain highly sensitive CMOS logic gates. When the central hydraulic control console is energized or the PLC is processing loops, never unplug or mate the 7-pin main connection plug. Hot-plugging creates localized micro-arcing and voltage sags that can instantly fry the LVDT processor or operational amplifiers.

• Execute System-Air Evacuation from Armature Cavities at Commissioning: Rebuilt systems or newly swapped valves naturally harbor localized air locks inside the solenoid armature tubes. While cycling the main pump at a low pressure threshold (10-20 bar), repeatedly toggle low-frequency cross-commands between ports A and B to cycle the spool, then slightly ease open the integrated air bleed screws. Torque them closed only after solid, bubble-free fluid emerges. Failing to clear air locks yields an unstable “soft spring” response, escalating hysteresis and inducing system oscillations.