Sun Hydraulics Cartridge Valves | RPGC-LCN CBCA-LHN RPEC-LCN CBBC-LIN

The Sun Hydraulics Interchangeable Series of screw-in cartridge valves (including models RPGC, CBCA, RPEC, CBBC, RVGA, and QPAB) manufactured by Chengyuan Hydraulic represents the pinnacle of precision fluid pressure control. These valves are engineered to strictly mirror the patented “Floating Construction” design of Sun Hydraulics, allowing internal components to self-align within the cavity. This engineering approach eliminates spool binding issues caused by excessive installation torque or machining eccentricities of the manifold. Every valve in this series, from pilot-operated relief valves to counterbalance and sequence valves, undergoes 100% simulated condition testing at Chengyuan’s facility. We verify every unit under a 350 bar continuous load to ensure that the installation dimensions, flow curves, and pressure response are 100% interchangeable with the original Sun Hydraulics cartridges, providing a seamless, high-performance alternative for global B2B hydraulic system integrators.

Technical Specifications :

• Brand Compatibility: Sun Hydraulics Interchangeable Series

• Target Model Codes & Functionality:

  • RPGC-LCN / RPGC-KDN: Pilot-operated, balanced piston relief valve. Flow: 380 L/min; Range: 70-210 bar (LCN) or 70-210 bar (KDN w/ handknob).

  • RPEC-LCN: Pilot-operated, balanced piston relief valve. Flow: 95 L/min; Ultra-compact design.

  • CBCA-LHN: Counterbalance valve (Load holding). Pilot Ratio: 3:1; Flow: 60 L/min.

  • CBBC-LIN: Counterbalance valve (Load holding). Pilot Ratio: 3:1; Flow: 40 L/min.

  • RVGA-LCN: Direct-acting relief valve. High-speed response for spike protection.

  • QPAB-LCN: Pilot-operated, balanced piston sequence valve with external drain.

• Maximum Rated Operating Pressure: 350 bar (5000 PSI)

• Maximum Tank Backpressure: Unaffected by backpressure (Specific to pilot-operated models)

• Adjustment Suffixes: L = Standard Leak-proof Screw; K = Handknob Adjustment

• Elastomer Seals: Buna-N (Standard) or Viton (High-temperature option)

Key Technical Advantages:

• Patented-Style Two-Piece Floating Construction: Chengyuan replicates the unique two-piece floating design that isolates the moving spool from external manifold stresses. This ensures the valve operates smoothly even if the cavity is slightly out of square or if installation torque exceeds specified limits, significantly reducing field failure rates.

• Hardened Alloy Steel Seating Interface: Components such as the poppets and seats in the RPGC and CBCA models undergo vacuum-ion nitriding. With a surface hardness exceeding HRC 60, our valves offer exceptional resistance to erosive wear and fluid contamination, maintaining a “zero-leakage” seal over millions of cycles.

• Superior Dynamic Response & Low Hysteresis: By optimizing internal pilot orifice geometries, our RPEC/RPGC series minimizes pressure overshoot. With a response time $\le 20$ ms, these valves react instantly to system transients, protecting hydraulic pumps and actuators from destructive pressure spikes.

• Pre-Stressed Fatigue-Resistant Springs: Internal adjustment springs are made from imported SiCr alloy steel with a shot-peened finish. This ensures pressure setting stability with a deviation of less than 1% even after exhaustive high-pressure cycling.

Application Areas:

• Mobile Equipment Load Holding: Balancing circuits for excavator booms, crane winches, and aerial platforms (CBCA/CBBC).

• Hydraulic Power Units (HPU): Main system pressure relief and multi-stage pressure regulation (RPGC/RPEC).

• Industrial Press Systems: Precise logic control for sequential cylinder activation (QPAB).

Expert Maintenance Tips:

• Observe Strict Installation Torque Specifications: Despite the floating design, excessive torque can distort the manifold’s seating surface. For Series 1 cartridges, use 40-50 Nm; for Series 2, use 60-70 Nm. Always utilize a calibrated torque wrench for final installation.

• Cleanliness is Critical for Pilot-Operated Cartridges: The narrow pilot orifices in Sun-style valves are sensitive to debris. Ensure the manifold cavity is free of chips or burrs before installation. We recommend a filtration level of at least $\beta_{10} \ge 100$ in the main circuit.

• Inspect Adjustment Seals Periodically: In harsh environments (e.g., marine or mining), check the adjustment screw O-ring every 2000 hours. If oil seepage is detected at the screw head, replace the seal kit immediately to prevent moisture from entering the spring chamber and causing internal corrosion.