SUN Hydraulics Cartridge Valves | PRDB RPET DPBP SCCA Series | Pressure & Directional Control

The SUN Series cartridge valves provided by Chengyuan Hydraulic are high-precision hydraulic control components fully compatible with SUN Hydraulics industry standards. This range includes essential models such as Pressure Reducing/Relieving valves (PRDB), Pilot-operated Relief valves (RPET), and Sequence valves (SCCA). The defining feature of SUN valves is their Floating Architecture, which allows internal components to self-align within the cavity, preventing spool binding caused by manifold machining inaccuracies or excessive installation torque. Every valve undergoes 100% simulated condition testing to guarantee that pressure linearity and sealing performance match OEM benchmarks, ensuring 100% original-place interchangeability.

Technical Specifications :

• PRDB-KBN: Pilot-operated, reducing/relieving valve, Series 1, Flow 40 L/min, Range 7-210 bar.

• RPET-LAN: 2-stage, pilot-operated relief valve, Series 4, Flow up to 760 L/min, Max 350 bar.

• DPBP-LAN: Pilot-operated reducing valve with drain, Series 2, Flow 80 L/min.

• SCCA-CAN: Direct-acting sequence valve with check, Series 1, Flow 30 L/min.

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

• Installation Torque: According to specific series size (Series 1, 2, 3, 4).

• Seal Material: Buna-N (Standard) / Viton (Optional).

Key Technical Advantages:

• Floating Architecture: The internal valve assembly is isolated from the external threaded housing. This design absorbs stress from cavity misalignment, ensuring smooth spool movement and preventing “sticking” even under extreme pressure cycles.

• Superior Regulation Linearity: Utilizing advanced spring calibration and precision-machined pilot orifices, the PRDB and RPET series offer excellent linearity across the full adjustment range with minimal hysteresis.

• High Flow Density: Optimized internal flow paths allow for higher flow rates compared to traditional cartridges of the same size, enabling more compact manifold designs.

• Full-Load Dynamic Validation: Chengyuan tests each valve for cracking pressure, reseat pressure, and response time. Specifically for the RPET series, pilot response is calibrated to meet the demands of high-speed hydraulic circuits.

Application Areas:

• Construction Equipment: Pressure regulation for auxiliary systems in excavators and loaders.

• Industrial Manifolds: Complex hydraulic integrated circuits (HICs).

• Plastic Machinery: Precise control of clamping and injection pressures.

Expert Maintenance Tips:

• Torque Compliance: Despite the floating design, over-torquing can damage threads or the bottom seal seat. Always use a calibrated torque wrench to follow the specific values for each Series.

• System Cleanliness: The small pilot orifices (<1mm) are sensitive to contaminants. Maintain a filtration level of NAS Class 7 (10μm) or better.

• Seal Lubrication: Apply a thin film of hydraulic oil to the O-rings before installation to prevent cutting or tearing as the valve is threaded into the cavity.