DB10-1-50B/315 DB20-2-5X/345E DB20-2-5X/100X Rexroth Pressure Relief Valve

Product Overview

The DB/DBW series pilot-operated pressure relief valves are high-performance pressure control components engineered by Bosch Rexroth for industrial hydraulic systems, widely used for system pressure limitation and overload protection. The DB series provides precise system pressure limitation and protection; the DBW series integrates a solenoid directional valve on the DB series base, enabling solenoid-actuated system unloading or multi-stage pressure control at any time.

The DB/DBW series features a pilot-operated two-stage concentric design with both pilot and main stages utilizing poppet-type structures, offering fast response, low leakage, and excellent opening/closing characteristics. The series covers sizes from NG6 to NG32, supporting both subplate mounting and threaded cartridge configurations with ISO 6264 porting patterns.

Our complete range of Rexroth DB/DBW pressure valves strictly adheres to OEM technical standards, achieving 100% direct interchangeability with original components. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring performance parameters are fully consistent with genuine Rexroth products. Direct replacement of same-model Rexroth valves significantly reduces equipment downtime and maintenance costs.

⚠️ Model Code Decoding (using DB10-1-50B/315 as example) :

• DB = Pilot-operated pressure relief valve

• DBW = Pilot-operated pressure relief valve with solenoid unloading

• 10 / 20 / 30 = Nominal size (NG10 / NG20 / NG30)

• 1 / 2 = Adjustment type (1 = hexagon sleeve with protective cap; 2 = lockable rotary knob with scale)

• 50B = Design series (50B series)

• 5X = Component series (5X series)

• 315 / 345E / 100X = Set pressure (bar) and special configuration code

Technical Specifications 

DB10-1-50B/315

• Product Series: Bosch Rexroth DB series pilot-operated pressure relief valve

• Model Code: DB10-1-50B/315

• Brand: Rexroth

• Product Type: Pilot-operated pressure relief valve

• Nominal Size: NG10

• Component Series: 50B series

• Maximum Operating Pressure: 350 bar

• Set Pressure: Up to 315 bar

• Poppet Type: Cone poppet (both pilot and main stages)

• Mounting Type: Subplate mounting

• Porting Pattern Standard: ISO 6264 (NG10)

• Control Type: Pilot-operated, internal pilot oil supply

• Compatible Hydraulic Fluids: HL, HLP, HLPD, HVLP, HVLPD, HFC

• Sealing Material: NBR (standard)

DB20-2-5X/345E (R901280473)

• Product Series: Bosch Rexroth DB series pilot-operated pressure relief valve

• Model Code: DB20-2-5X/345E

• Material Number (MPN) : R901280473

• Brand: Rexroth

• Product Type: Pilot-operated pressure relief valve

• Nominal Size: NG25

• Component Series: 5X

• Maximum Operating Pressure: 350 bar

• Maximum Flow Rate: 400 – 650 L/min (configuration dependent)

• Set Pressure: 345 bar

• Mounting Type: Subplate mounting

• Porting Pattern Standard: ISO 6264 (NG25)

• Sealing Material: NBR (standard)

• Weight: Approx. 3.78 kg

DB20-2-5X/100X (R900596693)

• Product Series: Bosch Rexroth DB series pilot-operated pressure relief valve

• Model Code: DB20-2-5X/100X

• Material Number (MPN) : R900596693

• Brand: Rexroth

• Product Type: Pilot-operated pressure relief valve

• Nominal Size: NG25

• Component Series: 5X

• Maximum Operating Pressure: 350 bar

• Maximum Flow Rate: 400 L/min

• Set Pressure: Up to 100 bar

• Mounting Type: Subplate mounting

• Porting Pattern Standard: ISO 6264 (NG25)

• Sealing Material: NBR (standard)

• Weight: Approx. 3.78 kg

DBW Series (General Specifications)

• Product Series: Bosch Rexroth DBW series solenoid-operated pressure relief valve

• Product Type: Pilot-operated pressure relief valve with solenoid unloading

• Nominal Size: NG10 to NG32

• Component Series: 4X / 5X

• Maximum Operating Pressure: 350 bar

• Maximum Flow Rate: 250 L/min (NG10)to 650 L/min

• Control Type: Pilot-operated + solenoid unloading

• Solenoid Voltage: DC24V (standard)

Key Technical Advantages

1. Pilot-Operated Two-Stage Control for High-Precision Pressure Limiting
The DB/DBW series employs a two-stage design combining a pilot control valve with a main spool, with both stages utilizing poppet-type structures. System pressure is set via the pilot valve, with the main valve precisely opening for relief when the set pressure is reached. Compared to direct-acting relief valves, the pilot-operated design delivers superior pressure regulation accuracy and stability under high-pressure, high-flow conditions.

2. High Pressure Rating and Extensive Flow Capacity
The full series supports maximum operating pressures up to 350 bar. DB series flow capacities range from 250 L/min (NG10) to 650 L/min (NG32) . The DB20-2-5X/100X supports 400 L/min flow capacity, while the DB20-2-5X/345E achieves 400–650 L/min.

3. DBW Series with Integrated Solenoid Unloading
The DBW series integrates a 2/3 solenoid directional valve on the DB series base, enabling system unloading at any time via solenoid actuation. Via port X, the valve can be unloaded or switched to a secondary pressure setting, providing significant flexibility for multi-stage pressure control applications.

4. Superior Seal Compatibility and Corrosion Protection
Sealing materials available in NBR standard options, compatible with HL, HLP, HLPD, HVLP, HVLPD, and HFC hydraulic fluids. Valve bodies feature cast internal flow passages for excellent flow capacity and large flow rates. Optional corrosion-protected design enhances durability in harsh environments.

5. Flexible Pilot Oil Circuit Configurations and Multiple Adjustment Options
Supports multiple pilot oil supply and drain configurations including internal/external pilot supply and internal/external drain. Adjustment options include hexagon sleeve with protective cap, lockable rotary knob with scale, and rotary knob, accommodating diverse operational requirements.

6. 100% Direct Interchangeability and Simulated Condition Testing
All models strictly adhere to Rexroth original mounting dimensions and interface standards (ISO 6264), enabling direct drop-in replacement of original valves without piping modification or system adjustment. Every unit undergoes 100% simulated operating condition bench testing prior to shipment, ensuring consistent, stable performance at rated pressure and flow.

Application Areas

• Industrial Hydraulic Systems: Pressure limitation and overpressure protection for hydraulic power units and stations

• Construction & Earthmoving Machinery: Excavators, wheel loaders, cranes

• Injection Molding & Die-Casting: Hydraulic system pressure control and safety protection

• Metallurgical Equipment: Rolling mills, continuous casting equipment, lifting platforms

• DBW Series: Automated hydraulic systems requiring solenoid unloading or multi-stage pressure control

• Wind Power: Hydraulic pitch control systems, brake system pressure protection

• Mining Equipment: Pressure limitation for heavy mining machinery hydraulic systems

Expert Maintenance Tips

1. Verify Model Compatibility Prior to Installation
Confirm that the valve model matches system requirements—pay special attention to: nominal size (NG10/NG20/NG25/NG32), set pressure range, and mounting type (ISO 6264 subplate porting pattern). DB and DBW series serve different functions—DB provides pressure limitation only, while DBW additionally offers solenoid unloading—select accordingly based on system requirements.

2. Mounting Surface Cleanliness and Sealing
Ensure the mounting surface is clean and free of debris before subplate installation. Replace O-ring seals with new components and install correctly. Use a torque wrench to tighten mounting bolts diagonally to the torque values specified in Rexroth technical manuals to prevent valve body distortion or leakage.

3. System Cleanliness Management
Hydraulic system contamination is the leading cause of relief valve malfunction. Thoroughly flush system piping prior to installation. Recommended system cleanliness: ISO 4406 Class 18/16/13 or higher.

4. DBW Series Electrical Wiring Precautions
The DBW series integrates a solenoid directional valve for unloading functionality. Solenoid power supply is DC24V (standard configuration)—AC220V must never be connected. Verify supply voltage matches coil specifications prior to wiring.

5. Pressure Setting and Commissioning
Factory set pressure is nominal—recalibrate on-site according to actual system requirements. During commissioning, start from low pressure and gradually increase to the set value while monitoring pressure gauge response for smooth operation. DB/DBW series valves can be unloaded or switched to a secondary pressure setting via port X.

6. Periodic Maintenance and Inspection
Perform functional checks every 2,000 operating hours or annually, including: set pressure verification, leakage inspection (P→T ports), and response characteristic testing. DBW series additionally requires inspection of solenoid actuation reliability. If abnormal pressure fluctuation, sluggish response, or set pressure drift is observed, arrange for servicing or replacement.