Vickers CG5V Series Pilot Operated Pressure Relief Valve | CG5V-8FW CG5V-8GW | Solenoid Unloading Valve

The CG5V Series pilot-operated pressure relief valves with solenoid unloading manufactured by Chengyuan Hydraulic are high-performance engineering components designed to replace the technical standards of the industrial Eaton Vickers (now Danfoss) pressure control line. This heavy-duty series covers essential high-frequency replacement models, including CG5V-8FW-E-M-U-H7-11, CG5V-8FW-D-M-U-H7-11, and CG5V-8GW-E-M-U-H7-11.

Integrating a two-stage main stage relief function with a solenoid-actuated pilot valve, these components provide maximum system pressure protection (relief valve function) and allow for immediate automated electrical loading or unloading of full pump flow to the reservoir. Chengyuan guarantees 100% original-place interchangeability regarding standard subplate mounting patterns (complying with ISO 6264-10 and CETOP-RP 121H), manifold flow path dimensions, and control logic options. Every valve undergoes 100% simulated load testing under high pressure and high flow conditions prior to delivery to ensure rapid response times and ultra-low standby power losses.

Technical Specifications 

• Compatible Brand: Eaton Vickers / Danfoss

• Core Model Codes: CG5V-8FW-E-M-U-H7-11, CG5V-8FW-D-M-U-H7-11, CG5V-8GW-E-M-U-H7-11

• Valve Size: Size 8 (Interface conforms to ISO 6264-10)

• Maximum Flow Rate: 400 L/min (105 USgpm)

• Max Operating Pressure (Ports P, X): 350 bar (5000 psi)

• Max Back Pressure (Port T): 315 bar (4500 psi)

• Pressure Ranges (F / G): F range: up to 200 bar; G range: up to 315 bar

• Pressure Adjustment Element (W): Hex head screw with protective cap and locknut

• Pilot & Drain Configuration (D / E): D: Internal Pilot, External Drain; E: External Pilot, Internal Drain

• Solenoid Voltage (H7): 24 VDC standard configuration

• Electrical Connection (U): ISO 4400 (DIN 43650) interface with Manual Override option (M)

• Design Sequence: 11 Design (Installation parameters identical for designs 10-19)

Key Technical Advantages:

• Precision Two-Stage Precision Relief: Features a classic main spool and cone-type pilot assembly. When system pressure matches the predetermined setting, the main spool slides smoothly within a micron-level tolerance. The optimized pressure override ensures that almost the total system flow remains fully available for mechanical output right up until the exact valve setting is reached.

• Low Off-Load Power Dissipation: The integrated directional pilot valve efficiently controls pressure pathways within the main stage spring chamber. When electrical unloading is engaged, the main spool vents directly into Port T with exceptionally minimal flow restriction, radically slashing standby energy wastage and fluid ripples.

• Heavy-Duty Cast Iron Housing: The main valve body is cast from high-tensile alloy iron, optimizing resistance against structural deformation and pressure fatigue cycles. The central pilot cone and main spool are vacuum carbonitrided and precision-ground, delivering flawless zero-leakage characteristics upon fluid-path closure.

• Robust Weatherproof Coils: Equipped with fully sealed resin-encapsulated H7 (24V DC) solenoid coils that maintain outstanding insulation, vibration resistance, and thermal performance. Paired with a standard manual override button, it vastly extends service life under severe environmental constraints like die-casting foundries and offshore applications.

Application Areas:

• Die Casting & Forging Machinery: Installed in high-volume clamping circuits to deliver reliable solenoid safety unloading and precise overload restriction.

• Heavy-Duty Machining Centers: Integrated into centralized multi-pump power units to achieve multi-stage pressure shifting and demand-based system offloading.

• Wind Turbines & Marine Control Systems: Providing robust fluid circuit isolation and control in exposed, high-humidity offshore winch lines.

Expert Maintenance Tips:

• Verify Pilot/Drain Logic (D/E): Ensure exact alignment with system circuit drawings before replacement. D defines internal pilot with external drain, while E signifies external pilot with internal drain. If the pilot line connections are restricted due to mismatched model selection, the valve will completely fail to regulate or unload system pressure.

• Manual Override Reset: The manual override button (M) is designed strictly for dry setup or emergency commissioning. Ensure the manual option is completely disengaged afterward. If the valve remains manually locked down, it will fail to respond to incoming electrical control signals.

• Strict Fluid Cleanliness Requirements: As a high-precision, pilot-operated valve, the internal control orifices are highly vulnerable to contamination. Maintain systemic oil filtration strictly at ISO 4406 19/16/13 or better. Hard particulate matter or fiber debris can quickly cause the main spool to jam, disabling pressure accumulation or safety relief functions.