Rexroth DBD Series Relief Valve | DBDS10K | DBDS20K | DBDS30K | Direct Acting Relief Valve

The DBD Series direct-acting relief valves from Chengyuan Hydraulic are high-performance pressure control components fully compatible with Rexroth Series 1X standards. Designed for use as safety valves or pressure limiting valves, they protect hydraulic systems and actuators from overloading. For core models DBDS10K1X/200, DBDS20K1X/200, and DBDS30K1X/200 (where K denotes rotary knob adjustment), we feature a hardened and tempered poppet design. Every valve undergoes 100% dynamic relief testing before shipment to ensure sensitive cracking pressure and chatter-free operation at the set pressure (e.g., 200 bar), guaranteeing 100% original-place interchangeability.

Technical Specifications :

• Series Model: DBDS Series (Direct-acting poppet type)

• Nominal Sizes: 10 (NG10) / 20 (NG20) / 30 (NG30)

• Adjustment Type: K (Hand knob) / S (Hexagon socket) / P (With cap)

• Max Operating Pressure: Up to 400 bar (40 MPa)

• Pressure Adjustment Range (This unit): Up to 200 bar (20 MPa)

• Max Flow Rate (NG10): 50 L/min

• Max Flow Rate (NG20): 120 L/min

• Max Flow Rate (NG30): 250 L/min

• Fluid Temperature Range: -30°C to +80°C

• Mounting Type: Subplate / Threaded (G-port) / Screw-in cartridge

Key Technical Advantages:

• Contamination-Resistant Poppet Design: Unlike pilot-operated valves, the DBD series uses a direct-acting poppet that is highly tolerant of micro-particles in the oil. This ensures a tight seal and reliable pressure limitation even in harsh environments.

• Integrated Damping Mechanism: The internal poppet includes a fluid damping feature to absorb pressure pulsations. This eliminates the “whistling” or high-frequency vibration common in direct-acting valves during high-pressure flow, improving system acoustics.

• High-Precision Alloy Springs: For the 200 bar specification, we select springs with excellent linearity and fatigue resistance. Even after hundreds of thousands of relief cycles, pressure drift is kept within ±1%, ensuring long-term safety.

• Optimized Flow Characteristics: The valve body galleries are hydrodynamically compensated to ensure a smooth pressure-drop-to-flow curve during full opening, preventing abnormal backpressure spikes due to insufficient flow capacity.

Application Areas:

• Industrial HPUs: Used as primary relief valves or safety bypass valves.

• Mobile Machinery: Pressure limiting in auxiliary circuits for excavators or loaders.

• Test Rigs: Relief circuits requiring high-precision pressure cutoff and frequent actuation.

Expert Maintenance Tips:

• Pressure Setting Procedure: When adjusting the knob (K-type), rotate slowly from low to high pressure while monitoring the gauge. Never force the adjustment bolt when the system is under pressure to avoid damaging spring seats.

• Backpressure Sensitivity: In direct-acting valves, backpressure at the return port (Port T) adds directly to the cracking pressure. Ensure the return line is unobstructed to prevent the actual opening pressure from exceeding the setpoint.

• Valve Seat Cleaning: If the valve fails to seal, it is often due to debris on the poppet face. When cleaning, handle with care to avoid scratching the precision sealing line of the seat.