Yuken EFBG Series Proportional Valve | EFBG-03-125 EFBG-06-500 | Relief & Flow Control

The EFBG Series electro-hydraulic proportional relief and flow control valves by Chengyuan Hydraulic are high-precision components designed for the automation of complex hydraulic cycles. Fully compatible with Yuken industrial standards, the core range features EFBG-03-125 (Size 10) and EFBG-06-500 (Size 25). The dual-function design allows for simultaneous, independent proportional control of system pressure (relief) and flow rate (actuator speed) via a single integrated valve block. As a signature product from Chengyuan, every EFBG valve undergoes 100% dynamic performance testing under simulated conditions, ensuring 100% original-place interchangeability in terms of repeat accuracy and frequency response.

Technical Specifications :

• Core Models: EFBG-03-125-H-20, EFBG-06-500-C-51, EFBG-03-125-H-60

• Max Operating Pressure: Up to 24.5 MPa (245 bar / 3550 psi)

• Pressure Adj. Range (H-Type): 1.0 – 21 MPa (145 – 3045 psi)

• Pressure Adj. Range (C-Type): 1.0 – 14 MPa (145 – 2030 psi)

• Rated Flow Rate (Size 03): 125 L/min (33 GPM)

• Rated Flow Rate (Size 06): 500 L/min (132 GPM)

• Rated Current (Solenoids): 0 – 800 mA / 0 – 900 mA (DC 24V)

• Hysteresis: ≤ 3%

• Repeatability: ≤ 1%

• Mounting Standard: ISO 6264 compliant subplate mounting

Key Technical Advantages:

• Integrated Multi-Functional Control: By merging proportional relief and flow control, the EFBG series minimizes system plumbing requirements. This compact integration reduces potential leak points and significantly shortens the hydraulic response cycle.

• High-Performance Proportional Solenoids: Equipped with self-developed low-hysteresis solenoids. The oil-immersed armature ensures smooth motion and high linearity when driven by a power amplifier, providing shock-free speed transitions for actuators.

• Optimized Pilot Stage Construction: The pilot relief section utilizes hardened conical spools for superior sealing and contamination resistance. This ensures the set pressure remains stable without thermal drift during extended high-pressure operation.

• Low Pressure-Drop Internal Geometry: The valve body is cast from high-tensile materials and optimized through CFD. Even at 500 L/min, the internal pressure loss is minimized, effectively reducing heat generation and extending fluid service life.

Application Areas:

• Injection Molding Machines: Multi-stage proportional control for injection pressure and speed.

• Hydraulic Presses: Precision speed and pressure switching for metal bending and stretching.

• Die-Casting Equipment: Flow regulation tailored for complex mold filling processes.

• Heavy Industrial Automation: Smooth start-stop control for conveyors and synchronized lifting of heavy loads.

Expert Maintenance Tips:

• Air Bleeding Procedure: During initial startup or after long idle periods, always use the air vent screws on the solenoids to bleed air. Trapped air causes control oscillations (hunting), which impairs smooth regulation.

• Fluid Cleanliness Standard: Proportional valves are highly sensitive to particulate contamination. Systems must utilize a 10μm (or finer) filter to maintain oil cleanliness at NAS Class 9 or ISO 4406 18/16/13 or better.

• External Drain (Y Port): As a pilot-operated valve, the external drain port (Y port) must be piped directly back to the tank. Ensure backpressure does not exceed 0.2 MPa, as excessive backpressure will interfere with proportional pressure accuracy.