SUN Hydraulics Cartridge Valve RDDA-LAN DTDA-MHN NCFB-LCN | Screw-in Hydraulic Control Valves

Chengyuan Hydraulic presents a high-performance lineup of screw-in cartridge valves designed as superior replacements for SUN Hydraulics standards. This range includes pressure control (RDDA), directional control (DTDA, DAAA), flow control (NCFB), and check valves (CNCE, CNHC). The engineering soul of SUN-style valves lies in their unique “Floating Construction.” At Chengyuan, we meticulously replicate this critical design, ensuring the valve internal components remain perfectly aligned regardless of installation torque fluctuations. Our products guarantee 100% Drop-in Interchangeability with standard SUN cavities (e.g., T-10A, T-13A, T-162A). Supported by our 100% Simulation Load Testing, every valve is validated for internal leakage, cracking pressure, and flow-pressure drop at rated loads before shipping, delivering original-equipment reliability at a competitive price.

Technical Specifications 

• RDDA-LAN (Relief Valve): Direct-acting, 350 bar (5000 psi) rated pressure, 95 L/min max flow, T-10A cavity.

• DTDA-MHN (Directional Valve): Solenoid-operated, 2-way, 2-stage poppet valve, 350 bar rated, 40 L/min max flow, T-13A cavity.

• DAAA-MCN (Directional Valve): Solenoid-operated, 2-way, direct-acting spool valve, 350 bar rated, 1 L/min max flow (Pilot stage), T-8A cavity.

• NCFB-LCN (Needle Valve): Pressure compensated fixed orifice flow control, 350 bar max pressure, T-13A cavity.

• CNCE-XCN (Check Valve): Pilot-to-close check valve, 350 bar rated, 60 L/min max flow.

• Component Material: High-strength alloy steel (60HRC) internals; aero-grade aluminum or hardened steel valve bodies.

• Seal Options: Buna-N (Standard); Viton (Available for high temperatures/special fluids).

Key Technical Advantages:

• Floating Construction Technology: Adopting the iconic two-stage structural design allows the valve assembly a slight radial float. This prevents spool binding often caused by machining tolerances in the manifold cavity.

• Ultra-Low Leakage Poppets: The poppet series (e.g., DTDA) features precision-ground seats and hardened poppets, achieving near-zero leakage at 350 bar, maximizing system holding efficiency.

• Contamination Resistance: Optimized spool edges with self-cleaning grooves effectively purge particulate matter, ensuring reliable operation even in less-than-ideal fluid conditions.

• High-Frequency Stability: Core components undergo deep nitriding and high-frequency quenching, maintaining geometric precision and preventing performance drift after millions of cycles.

Application Areas:

• Hydraulic Integrated Circuits (HIC): Customized manifold blocks for controlling actuator pressure and direction.

• Construction Machinery: Excavator pilot circuits, loader lifting systems, and forklift control valves.

• Industrial Presses: Pressure holding, emergency unloading, and sequential operation logic.

• Agricultural Equipment: Tractor auxiliary hydraulic outputs and harvester automation.

Expert Maintenance Tips:

• Torque Specifications: Although designed with floating construction, strictly follow the recommended installation torque to prevent O-ring damage or permanent sleeve deformation.

• Filtration Standards: System oil cleanliness should be maintained at ISO 4406 18/16/13 or better to ensure small pilot orifices remain unobstructed.

• Seal Integrity: Always inspect the external O-rings and back-up rings before installation to prevent internal bypass within the manifold block.