SUN Hydraulics Cartridge Valve Replacement | PVFA-LAN RPIC-LAN RPKC-LAN | Pressure & Flow Control Valves

Chengyuan Hydraulic presents a high-performance lineup of SUN Hydraulics Series cartridge valve replacements. Our range includes proportional flow control (PVFA), pilot-operated relief (RPIC/RPKC), direct-acting relief (RBAC/RBAA), pressure regulation (RPGS/RPIS), and flow dividers (FDCB). The engineering soul of SUN valves lies in their iconic Floating Construction. Chengyuan’s manufacturing process meticulously replicates this design, allowing the valve sleeve to “float” radially within the cavity. This feature effectively prevents spool binding caused by machining tolerances or excessive installation torque. All models provide 100% Drop-in Interchangeability. With Chengyuan’s 100% Simulation Load Testing, each valve is validated for dynamic response and leakage under rated loads, ensuring performance parity with original standards in heavy-duty environments.

Technical Specifications 

• PVFA-LAN: Proportional throttle valve, pilot-operated, T-11A cavity, 350 bar max, 24 L/min rated flow.

• RPIC-LAN: Pilot-operated relief valve, T-10A cavity, 350 bar max, 95 L/min max flow.

• RPKC-LAN: Pilot-operated relief valve, T-162A cavity, 350 bar max, 380 L/min max flow.

• RBAC-LAN: Direct-acting relief valve, T-163A cavity, 350 bar max, 18 L/min max flow.

• RBAA-LAN: Direct-acting relief valve, T-8A cavity, 350 bar max, 1 L/min max flow (for pilot control).

• RPGS-LAN: Pilot-operated relief valve, T-3A cavity, 350 bar max, 200 L/min max flow.

• RPIS-LAN: Pilot-operated relief valve, T-16A cavity, 350 bar max, 380 L/min max flow.

• FDCB-HAN: Flow divider/combiner (fixed ratio), T-11A cavity, 350 bar rated, 1.5 – 23 L/min range.

Key Technical Advantages:

• Floating Sleeve Technology: Adopting the classic two-stage design, the valve assembly allows for self-alignment during installation. This eliminates spool binding even if the manifold cavity has minor positioning errors, ensuring high sensitivity.

• Superior Volumetric Efficiency: Using precision-ground hardened alloy steel, the valve seats achieve near-zero leakage, significantly reducing heat generation in systems during standby, particularly in the RPIC/RPKC series.

• Contamination Resistance: Internal parts are heat-treated to 60-62 HRC. Optimized fluid passages feature self-cleaning properties, effectively handling erosion from fine particulates in complex hydraulic systems.

• Dynamic Stability: Validated by Chengyuan’s 100% load testing, these valves exhibit minimal pressure overshoot during rapid transients, protecting pumps and piping from hydraulic shock.

Application Areas:

• Mobile Machinery: Auxiliary circuit control for excavators and loaders.

• Industrial Presses: Pressure stage regulation and protection for precision forming machinery.

• Hydraulic Integrated Circuits (HIC): Pressure management, safety relief, and flow compensation in custom manifolds.

• Agricultural Equipment: Flow distribution in tractor hitch systems and steering circuits.

Expert Maintenance Tips:

• Torque Management: Despite the floating design, strictly adhere to the torque specifications in the SUN technical manual. Excessive torque can damage O-rings or cause fatigue in the valve body.

• Air Bleeding: When operating proportional valves (e.g., PVFA) for the first time, cycle the valve several times at low pressure to exhaust trapped air and prevent oscillation.

• Filtration Standards: Maintain oil cleanliness at ISO 4406 19/17/14 or better to prolong the life of precision pilot orifices.