DBD Series Hydraulic Relief Valve | DBDS6 DBDS10 DBDS20 DBDS30 | 31.5MPa Direct Acting | Rexroth Replacement

The DBD Series direct-acting relief valves by Chengyuan Hydraulic are precision-engineered safety components designed to limit and maintain system pressure in hydraulic circuits. Fully compatible with Rexroth DBDS technical standards, this series provides 100% original-place interchangeability for sizes DBDS6, 10, 20, and 30. Utilizing high-strength hardened steel seats and precision-ground poppet/ball structures, our valves ensure zero leakage and rapid response even at pressures up to 31.5 MPa. Every DBD valve undergoes 100% simulated condition testing at Chengyuan to guarantee robust safety and performance for your heavy-duty hydraulic machinery.

Technical Specifications 

• Series Code: DBDS Series (Direct Acting)

• Nominal Sizes (NG): 6, 10, 20, 30

• Max Operating Pressure: 31.5 MPa (4568 psi / 315 bar)

• Maximum Flow Capacity:

  • NG6: $50\text{ L/min}$

  • NG10: $120\text{ L/min}$

  • NG20: $250\text{ L/min}$

  • NG30: $330\text{ L/min}$

• Pressure Adjustment Range: $2.5$ to $31.5\text{ MPa}$ (multiple spring options available)

• Adjustment Type: Hand knob (K), bolt with protective cap, or lockable knob

• Installation: Subplate mounting, Threaded (In-line) connection, or Cartridge insertion

• Weight: Varies by size (approx. $0.5\text{ kg to 4.5 kg}$)

Key Technical Advantages

• Instantaneous Response: The direct-acting spring-loaded design allows for much faster opening times compared to pilot-operated valves, providing immediate relief for pressure spikes and protecting sensitive system components.

• Hardened Steel Core for Durability: Spools and seats are crafted from high-carbon chrome steel with HRC 58-62 hardness. This provides exceptional resistance to cavitation and erosion under high-velocity oil flow.

• Anti-Vibration & Low Noise: Optimized internal damping chambers reduce pressure oscillations and eliminate high-frequency squealing during discharge, enhancing system stability and comfort.

• 100% Simulated Reliability Testing: At Chengyuan, every DBD valve is tested for set-pressure accuracy and leakage under peak simulated loads, ensuring no pressure drift even after tens of thousands of cycles.

Application Areas

• Industrial Machine Tools: Serving as the primary safety relief valve for hydraulic power units.

• Mobile Machinery: Pressure limiting in pilot circuits for loaders, excavators, and compactors.

• Marine Hydraulics: Overload protection for winches, cranes, and anchor handling systems.

Expert Maintenance Tips

• Periodic Recalibration: Springs can suffer from mechanical fatigue over time. We recommend re-checking the cracking pressure every 6 months to ensure system safety.

• Fluid Cleanliness: Due to the precise metal-to-metal seating, maintain oil cleanliness at ISO 4406 18/16/13 or better to prevent debris from causing sticking or leakage.

• Tank Port Connection: The T-port (drain) should be connected directly to the reservoir without backpressure. High backpressure at the return port will cause the cracking pressure to rise non-linearly.