DBW20B2-5X/350S6EG24N9K4R12 | Rexroth Solenoid Relief Valve 350bar 650L/min

DBW20B2-5X/350S6EG24N9K4R12

Product Overview

The DBW20B2-5X/350S6EG24N9K4R12 is a Bosch Rexroth DBW series pilot-operated solenoid relief valve, nominal size NG25, with mounting pattern conforming to ISO 6264-08-13. The DBW series adds a solenoid directional valve to the DB series relief valve, enabling system pressure limiting and remote solenoid-actuated unloading. The valve consists of three main components: the main valve (with main spool insert), the pilot control valve (with pressure adjustment element), and the integrated directional spool valve.

The DBW20B2-5X/350S6EG24N9K4R12 features B spool symbol (P→T flow path) , 5X component series, a maximum pressure setting of 350 bar, and a maximum operating pressure of 350 bar. This model is equipped with switching shock damping, which delays the opening from B to B via a sandwich plate design to mitigate pressure peaks and acoustic decompression shocks in the return line.

Model Code Breakdown:

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

• 20: Nominal Size NG20 (NG25 interface)

• B2: Spool symbol and configuration (B type, P→T)

• 5X: 5X Component Series (50–59)

• 350: Pressure setting (350 bar)

• S6: With switching shock damping

• EG24: DC 24V supply (E=wet solenoid, G=DC)

• N9: With manual override

• K4: Without cable socket

• R12: Switching shock damping configuration code

Technical Specifications (Bulleted List)

• Model: DBW20B2-5X/350S6EG24N9K4R12

• Material Number: R900922037

• Brand: BOSCH REXROTH

• Series: DBW Series, 5X Component Series

• Product Type: Pilot-operated Solenoid Relief Valve

• Spool Symbol: B type (P→T)

• Nominal Size: NG25 (DN25)

• Mounting Standard: ISO 6264-08-13

• Mounting Type: Subplate Mounting

• Maximum Operating Pressure: 350 bar (5075 psi) 

• Maximum Flow Rate: 500–650 L/min (configuration dependent)

• Pressure Setting Range: 4–350 bar

• Coil Voltage: 24V DC

• Electrical Connector: 3-pin device plug (2 + PE) per EN 175301-803

• Protection Class: IP65 (with properly installed connector)

• Seal Material: NBR

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

• Adjustment Types: Multiple (rotary knob, hexagon sleeve, etc.)

• Weight: 5.92 kg

DBW10A-2-50/200-6AG24Z5L

Product Overview

The DBW10A-2-50/200-6AG24Z5L (Material Number R900523062) is a Bosch Rexroth DBW series pilot-operated solenoid relief valve, nominal size NG10, with mounting pattern conforming to ISO 6264-06-09. The DBW series adds a solenoid directional valve to the DB series relief valve, enabling system pressure limiting and remote solenoid-actuated unloading.

The valve consists of three main components: the main valve (with main spool insert), the pilot control valve (with pressure adjustment element), and the integrated directional spool valve. The DBW10A-2-50/200-6AG24Z5L features B spool symbol (P→T flow path) , 50 series design, a maximum pressure setting of 200 bar, and a maximum operating pressure of 350 bar. Z5L is a specific option code.

Model Code Breakdown:

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

• 10: Nominal Size NG10

• A-2: Spool symbol and configuration (A type)

• 50: 50 Series Design

• 200: Pressure setting (200 bar)

• 6A: With wet-type solenoid

• G24: DC 24V supply (G=DC)

• Z5L: Specific option/configuration code

Technical Specifications (Bulleted List)

• Model: DBW10A-2-50/200-6AG24Z5L

• Material Number: R900523062

• Brand: BOSCH REXROTH

• Series: DBW Series, 50 Series Design

• Product Type: Pilot-operated Solenoid Relief Valve

• Spool Symbol: B type (P→T)

• Nominal Size: NG10

• Mounting Standard: ISO 6264-06-09

• Mounting Type: Subplate Mounting

• Maximum Operating Pressure: 350 bar (5000 psi)

• Maximum Pressure Setting: 200 bar (2900 psi)

• Coil Voltage: 24V DC

• Option Code: Z5L

• Protection Class: IP65

• Seal Material: NBR (standard)

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

Key Technical Advantages (DBW Series Common)

1. Pilot-Operated Design — High-Pressure High-Flow with Precise Control

The DBW series features pilot-operated construction—the main valve is controlled by a pilot control valve. Compared to direct-acting relief valves, the pilot-operated design delivers superior pressure/flow stability, lower hysteresis, and more precise pressure control. Maximum operating pressure reaches 350 bar with flow capacity up to 650 L/min.

2. Integrated Solenoid Unloading — Remote Pressure Control

The DBW series adds a solenoid directional valve to the DB series relief valve, enabling remote solenoid-actuated system pressure unloading. When energized, the directional valve actuates, unloading system pressure to tank through the pilot valve. This allows the DBW valve to serve both as a system safety valve and a remote unloading valve.

3. B Spool Symbol — Direct P→T Unloading Flow Path

Both models feature B spool symbol (P→T flow path) . When the solenoid is energized, pressure oil at the P port flows directly to the T port for rapid system pressure release.

4. Switching Shock Damping — Reduced System Noise and Shock (DBW20B2-5X/350S6EG24N9K4R12)

The DBW20B2-5X/350S6EG24N9K4R12 is equipped with switching shock damping. The delayed opening from B to B via the sandwich plate design effectively mitigates pressure peaks and acoustic decompression shocks in the return line. The damping level can be adjusted by selecting the appropriate nozzle size. This feature is particularly beneficial for reducing system noise and enhancing operational stability.

5. Multiple Pressure Grades and Adjustment Types

The DBW series offers 5 pressure grades. DBW20B2-5X/350S6EG24N9K4R12 covers a pressure setting range of 4–350 bar. 4 adjustment types are available: rotary knob, sleeve with hexagon and protective cap, lockable rotary knob with scale, and rotary knob with scale.

6. International Standard Compliance for Global Interchangeability

DBW20B2-5X/350S6EG24N9K4R12 mounting conforms to ISO 6264-08-13 (NG25). DBW10A-2-50/200-6AG24Z5L mounting conforms to ISO 6264-06-09 (NG10). The DBW series offers complete interchangeability with globally adopted interfaces.

Application Areas

DBW20B2-5X/350S6EG24N9K4R12 (NG25, High-Flow, with Switching Shock Damping):

• Heavy-Duty Hydraulic Systems — Pressure control and unloading for rolling mills, forging equipment

• Injection Molding Machinery — System pressure setting and unloading for large injection molding machines

• Die-Casting Machines — Pressure control for high-pressure casting equipment

• Large Hydraulic Power Units — Remote pressure unloading for high-flow hydraulic systems

DBW10A-2-50/200-6AG24Z5L (NG10, 200 bar Setting):

• Fixed-Displacement Pump Systems — System pressure limiting and remote unloading control

• CNC Machine Tools — Hydraulic system pressure limiting and unloading

• Industrial Automation Production Lines — Hydraulic systems requiring remote pressure unloading

• General Industrial Hydraulic Systems — Various applications requiring pressure control and unloading

Expert Maintenance Tips

1. Installation Guidelines

• DBW20B2-5X/350S6EG24N9K4R12 mounting must conform to ISO 6264-08-13 (NG25).

• DBW10A-2-50/200-6AG24Z5L mounting must conform to ISO 6264-06-09 (NG10).

• Thoroughly clean the mounting surface and all ports (P, T) before installation to prevent foreign particles from entering and causing spool sticking or seal damage.

• Tighten mounting bolts evenly to the specified torque to ensure proper sealing between the valve body and mounting surface.

2. Hydraulic Fluid Cleanliness

• Compatible fluids: HL, HLP, HLPD, HVLP, HVLPD, HFC.

• Seal material: NBR.

• Recommended fluid cleanliness: ISO 4406 19/17/14 or better.

• Install a return line filter with minimum 10 μm filtration rating.

3. Pressure Setting Adjustment

• DBW20B2-5X/350S6EG24N9K4R12 setting range: 4–350 bar.

• DBW10A-2-50/200-6AG24Z5L maximum setting: 200 bar.

• Pressure adjustment is performed via the adjustment element on the pilot valve—turn clockwise to increase, counterclockwise to decrease.

• Adjust gradually under system operating conditions to achieve the desired pressure value.

4. Electrical Connection Specifications

• Both models use 24V DC supply.

• Electrical connector: 3-pin device plug (2 + PE) per EN 175301-803.

• Ensure the connector is fully locked to maintain effective protection.

5. Switching Shock Damping Adjustment (DBW20B2-5X/350S6EG24N9K4R12)

• The damping level can be adjusted by selecting the appropriate nozzle size.

• The R nozzle code is recommended for optimal performance.

• Refer to Rexroth technical documentation for damping characteristic adjustments.

6. Solenoid Unloading Function Usage

• When the DBW series solenoid is energized, system pressure is unloaded to tank pressure through the pilot valve.

• When de-energized, the valve returns to normal relief function.

• The unloading function can be used for system standby energy saving or emergency pressure release.

7. Periodic Maintenance Inspection

• Inspect the valve body for external oil leakage every 2,000 operating hours or at least annually.

• Check electrical connectors for looseness, oxidation, or moisture ingress.

• If pressure control instability or slow response is observed, first check system fluid cleanliness and verify the pilot spool is not sticking.