Sun Hydraulics Relief Valve RPEC-LAN RVGA-LWN | Pilot Operated Cartridge Valve

Chengyuan Hydraulic offers a premium range of screw-in cartridge valves designed as superior replacements for the Sun Hydraulics standards. This portfolio covers pilot-operated balanced piston relief valves (RPEC, RVGA), check valves (CXJA), and pressure-compensated flow controls (RSFC). The engineering soul of Sun-style valves lies in their unique “Floating Construction.” Chengyuan meticulously replicates this design, ensuring the internal working parts remain coaxial even under installation torque variations, effectively preventing spool sticking. These valves provide 100% Drop-in Interchangeability with T-10A, T-3A, T-13A, and T-11A cavities. Backed by Chengyuan’s 100% Simulation Load Testing, each cartridge is verified at 350 Bar for pressure linearity and leakage integrity, making them the ideal choice for high-pressure integrated manifolds.

Technical Specifications 

• Compatible Brand: Sun Hydraulics

• Core Model Codes: RPEC-LAN, RVGA-LWN, CXJA-XCN, RSFC-LEN

• Max. Operating Pressure: 350 Bar (5000 psi)

• Flow Capacity:

  • RPEC-LAN: 95 L/min (25 gpm)

  • RVGA-LWN: 240 L/min (60 gpm)

  • RSFC-LEN: 11 – 45 L/min (Model dependent)

• Cavity Specifications: T-10A, T-3A, T-13A, T-11A

• Material Process: Aerospace-grade alloy steel housing with vacuum heat-treated internal components.

• Seals: NBR (Standard) or FKM (Viton) for high-temperature durability.

• Control Types: Pressure compensated, pilot-operated relief, free-flow check.

Key Technical Advantages:

• Torque Insensitivity (Floating Design): Featuring a two-stage sealing and floating internal sleeve. Even if field installation torque exceeds recommended limits, the precision matching parts remain undeformed. This ensures consistent operation and eliminates pressure spikes in harsh mobile environments.

• Superior Pressure Linearity: The RPEC and RVGA series utilize a balanced piston design, resulting in a minimal pressure rise between cracking and full flow. At a continuous 350 Bar, pressure fluctuations are kept within ±1.5%, protecting sensitive downstream components.

• Low Hysteresis & Long Service Life: Spools are super-finished and paired with precision springs. With a hysteresis error of less than 2% and an operational life exceeding 10 million cycles, our valves offer unmatched reliability. The RSFC series provides precise flow stability despite varying load pressures.

• Compact Integration: Compared to traditional subplate valves, Chengyuan’s Sun-style cartridges reduce volume by approximately 60%. They are perfect for space-constrained manifolds in excavators and drilling rigs, simplifying piping and reducing internal leakage paths.

Application Areas:

• Mobile Equipment: Main relief protection for excavators and load-sensing systems in loaders.

• Industrial Manifolds: Custom hydraulic power unit (HPU) circuits for pressure regulation.

• Mining Machinery: Pressure stabilization and safety protection for rock drills and haul trucks.

• Wind Energy: Yaw and pitch control systems requiring high-pressure stability.

Expert Maintenance Tips:

• Installation Torque: While the floating design is robust, a torque wrench is highly recommended. For example, T-10A cavities usually require 40-50 Nm. Excessive torque can still shorten seal life.

• Filtration Standards: Pilot-operated valves are extremely sensitive to contaminants. Maintain system fluid at ISO 4406 18/16/13 or cleaner. Dirty oil can clog pilot orifices, leading to pressure adjustment failure.

• Air Purging: Upon initial startup or after valve replacement, cycle the system several times at low pressure to purge air from the pilot chambers. Trapped air can cause high-frequency noise or “whistling.”