Vickers CG2V Relief Valve CG2V-6FW-10 CG2V-8FW-10 CG2V-8GW-1

The industrial-grade Vickers / Eaton Compatible CG2V Series Pilot Operated Pressure Relief Valves, engineered by Chengyuan Hydraulic, are premium fluid-power control elements configured for high-capacity pressure containment, stabilizing system regulation, and safety limits. Operating as the primary defensive barrier and constant-pressure foundation for main hydraulic power networks, this series leverages an ultra-sensitive pilot mechanism to deliver stable pressure control curves and minimized transient pressure overshoots under punishing maximum-flow workloads.

This high-performance valve group targets the global B2B industrial component marketplace and hydraulic system building sectors, delivering 100% direct drop-in interchangeability with classic Vickers reference part codes, including: CG2V-6FW-10, CG2V-8FW-10, and CG2V-8GW-1 (typically encompassing the standard 10 design catalog and subsequent sub-generation architectures). The portfolio provides deep coverage across two critical industrial volumetric framing sizes: Nominal Size 20 mm (CG2V-6) and Nominal Size 25 mm (CG2V-8).

Chengyuan’s alternative pilot relief valves are manufactured in strict accordance with original Vickers technical geometry and performance guidelines. Every primary mounting variable—including the footprint configuration for subplate mounting, internal control oil routing configurations (standard “W” code internal-pilot/internal-drain layouts), and the manual adjustment spindle pitch—perfectly mirrors native technical specifications. During routine maintenance or component replacement cycles, field technicians can slide the new valve assembly directly onto existing manifold baseplates without altering rigid high-pressure pipe systems.

Main relief valves function at the core of heavy fluid-shearing zones, where continuous high-velocity dumping can cause spool edge scuffing, material fatigue, or main core binding driven by localized micro-carbonization of the fluid. To eliminate early field failures, 100% of Chengyuan’s CG2V series valves undergo 100% strict dynamic simulation testing on digital load blocks. Tested past 250 bar on specialized high-flow diagnostic benches, every unit is certified for precise pressure override limits, millisecond-range cracking response times, and zero static leakage across the pilot poppet seat to ensure reliable performance on factory floors.

Technical Specifications

• Product Classification: Pilot Operated, Subplate Mounted Pressure Relief Valve / Master Circuit Pressure Control Component

• Compatible Reference Platform Series: Flawless adaptation for Vickers / Eaton CG2V-6 and CG2V-8 series platforms (Design Series 10 and related evolutionary formats)

• Nominal Sizing Footprint & Standard Compliances:

  • CG2V-6 Product Line: Nominal Size 20 mm (tailored for standard 3/4-inch universal industrial subplate interfaces)

  • CG2V-8 Product Line: Nominal Size 25 mm (tailored for standard 1-inch universal industrial subplate interfaces)

• Maximum Permissible Circuit Pressure Rating (P Port): Up to 250 bar (25 MPa / 3625 psi)

• Maximum Volumetric Flow Rate Capacity:

  • CG2V-6 Series Form Factor: Continuous flow capacity up to 200 L/min (53 GPM)

  • CG2V-8 Series Form Factor: Continuous flow capacity up to 380 L/min (100 GPM)

• Technical Model Coding Decoupling & Precision Parameters:

  • Replacement Reference: CG2V-6FW-10

    • Configuration: Size 20 mm subplate valve; “F” designates a high-stiffness pressure regulating range spring targeting peak system relief settings from 210 to 250 bar; “W” specifies internal pilot oil supply from pressure port P alongside internal pilot fluid drainage routed straight back into tank port T; “10” marks the primary technical engineering design series.

  • Replacement Reference: CG2V-8FW-10

    • Configuration: Large-bore Size 25 mm subplate valve; engineered with expanded internal chambers to accommodate high flows up to 380 L/min; configured with an “F” code high-pressure limit regulating spring; “W” internal pilot/drain architecture; matched to the 10 design platform for massive pump station overpressure protection.

  • Replacement Reference: CG2V-8GW-1

    • Configuration: Large-bore Size 25 mm subplate valve; “G” denotes a low-to-medium pressure range high-sensitivity control spring (e.g., targeted precision regulation spanning 35 to 100 bar); “W” internal pilot/drain network; design suffix “1” matching classic primary relief feed configurations.

• Internal Pressure Control Hysteresis Limits: <= 3% of peak adjusted rating (ensuring exceptionally responsive cracking-to-reseating performance)

• Target Fluid Cleanliness Criteria: Must strictly comply with ISO 4406 19/17/14 or NAS Class 8 parameters

• Component Net Weight: CG2V-6 valve assembly is approx. 5.2 kg; CG2V-8 valve assembly is approx. 8.4 kg.

Key Technical Advantages

• Hydrodynamically Balanced Main Spool with Radial Pressure Equalizing Grooves: The main sliding spool is machined from heavy-duty alloy bearing steel, heat-treated and induction-nitrided. Precision circumferential oil grooves are cut along the spool lands to equalize localized hydrostatic pressure during high-velocity bypass streams. This eliminates asymmetric lateral fluid forces, ensuring light spool movement and preventing hydraulic locking under continuous high-pressure conditions.

• Micro-Finished Nanometer-Class Pilot Poppet & Hardened Seat Assembly: The secondary pilot regulating stage is comprised of an ultra-hardened steel poppet matched to a super-finished circular seat orifice. The metal-to-metal sealing boundary undergoes micro-grinding to ensure excellent sealing integrity. This keeps internal pilot bypass leakage near zero before reaching cracking pressure, maximizing system volumetric efficiency.

• CFD-Optimized Low-Resistance Ductile Iron Casting Housing: The valve casing is molded from dense, high-grade ductile iron utilizing advanced resin-sand casting techniques. The optimized internal geometries lower fluid friction during full-capacity dumping cycles, minimizing pressure drop and heat generation caused by fluid shearing.

• Integrated Dual-Stage Acoustic Damping Assembly: The interior control circuit houses dedicated micro-orifice dampening plugs. This dampening network dampens pressure pulsations caused by high-frequency spool oscillation or rapid cracking transitions, ensuring smooth operation while lowering circuit noise and resonant pipeline vibrations.

Application Areas

Chengyuan’s rugged replacement Vickers CG2V-6 and CG2V-8 series pilot operated relief valves deliver precise pressure containment across heavy fluid systems:

• Central Hydraulic Power Units (HPUs) & Master Pump Stations: Positioned directly at the outlet of high-pressure piston or vane pumps to provide system safety and overpressure containment.

• Heavy Metal Cutting Machine Tools & Portal Milling Platforms: Managing pressure spikes and braking circuit deceleration profiles during high-speed table reversals.

• Heavy Marine Deck Machinery & Mobile Structural Systems: Integrated into the master control manifolds of large cranes, tunnel boring shields, or heavy excavators as the primary line of defense against external shock loads.

Expert Maintenance Tips

• Prior to Positioning the Proportional Valve on the Manifold, Verify System Fluid Cleanliness Complying with ISO 4406 19/17/14 via Direct Sampling: Pilot operated relief valves depend on small control orifices and pilot poppet clearances measured between 0.8 mm and 1.2 mm. If the oil contains fine particulate contaminants or sludge from a worn pump, these particles can block the control orifices. This can cause the main spool to stick in an open profile (failing to build pressure) or lock closed (causing overpressurization).

• Torque the Subplate Fastening Bolts Uniformly in a Cross-Pattern Grid Using a Calibrated Torque Wrench: Tighten CG2V-6 mounting bolts (Class 12.9) to precisely 30 N·m, and CG2V-8 mounting bolts to precisely 65 N·m. Uneven torque application or the use of impact drivers can induce minor physical distortion across the bottom face of the cast housing, increasing internal spool friction and leading to pressure regulation lag or sticking.

• If System Pressure Desired Settings Lag or if High-Frequency Acoustic Whining Occurs when the Spindle is Adjusted, Inspect the Pilot Seating Boundary First: Continuous high-pressure fluid shearing can cause microscopic erosion patterns on the pilot poppet face. Rather than simply installing a stiffer spring to force it closed, remove the pilot stage, clean the internal damping ports with a degreasing solvent, and inspect or replace worn pilot components to restore factory-spec pressure regulation.