DBW10B2-5X/100-6EG24NK4 | Rexroth Solenoid Relief Valve 350bar 250L/min

Product Overview

The DBW10B2-5X/100-6EG24NK4 (Material Number R900757733) is a classic model in the Bosch Rexroth DBW series of pilot-operated solenoid relief valves, NG10 (CETOP 5) size, with mounting pattern conforming to ISO 6264-06-09. This pilot-operated relief valve integrates a solenoid directional valve for remote system pressure unloading—used for limiting maximum system pressure and enabling solenoid-actuated remote unloading.

The DBW series valve consists of three main components: the pilot control valve (with pressure adjustment element), the main valve (with main spool insert), and the directional valve (optional). The DBW10B2-5X/100-6EG24NK4 features B spool symbol (P→T flow path), 5X series (50–59 series), and 24V DC supply.

As an original Bosch Rexroth pilot-operated solenoid relief valve, this product offers complete interchangeability within the same series and size, requiring no modifications to mounting interfaces or piping layouts.

Model Code Breakdown (DBW10B2-5X/100-6EG24NK4):

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

• 10: Nominal Size NG10 (10 mm)

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

• 5X: 5X Series (50–59, unchanged installation and connection dimensions)

• 100: Pressure setting (100 bar)

• 6E: With wet-type solenoid

• G24: DC 24V supply (G = DC)

• N: NBR seals

• K4: Without mating connector / connection box

Technical Specifications 

DBW10B2-5X/100-6EG24NK4 Specifications:

• Model: DBW10B2-5X/100-6EG24NK4

• Material Number: R900757733

• Brand: BOSCH REXROTH

• Series: DBW Series, 5X Component Series

• Product Type: Pilot-operated Solenoid Relief Valve

• Spool Symbol: B type (P→T) 

• Nominal Size: NG10 (10 mm)

• Mounting Standard: ISO 6264-06-09

• Maximum Operating Pressure: 350 bar (5075 psi) 

• Maximum Flow Rate: 250 L/min (66 GPM) 

• Pressure Setting: 100 bar

• Coil Voltage: 24V DC

• Solenoid Type: Wet-Pin Solenoid

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

• Protection Class: IP65 (with properly installed connector)

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

• Seal Material: NBR

• Body Material: High-strength cast iron

• Mounting Type: Subplate Mounting

• Weight: 4.54 kg

• Certifications: CE compliant

Key Technical Advantages

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

The DBW10B2-5X/100-6EG24NK4 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. The set pressure is maintained even at flow rates up to 250 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

The DBW10B2-5X/100-6EG24NK4 features 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. The B configuration is ideal for applications requiring direct unloading to tank.

4. 350 bar High Pressure and 250 L/min High Flow Capacity

Delivers 350 bar (5,075 psi) maximum operating pressure and 250 L/min (66 GPM) flow capacity in a compact NG10 valve body. This performance places it at the forefront of pilot-operated relief valves in its class, suitable for demanding medium-to-high pressure, high-flow hydraulic systems.

5. NBR Seals with Multi-Fluid Compatibility

Equipped with NBR seals, compatible with HL, HLP, HLPD, HVLP, HVLPD, HFC, and other hydraulic fluids. Suitable for mineral oil and water-containing fluid systems.

6. International Standard Compliance for Global Interchangeability

Mounting conforms to ISO 6264-06-09 international standards. The DBW series offers complete interchangeability with Parker, Eaton/Vickers, Atos, and other major brands. CE certification ensures compliance with EU safety regulations.

Application Areas

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

• Injection Molding Machinery — System pressure setting and unloading

• Hydraulic Presses and Forging Equipment — System pressure limiting and remote unloading

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

• CNC Machine Tools — Hydraulic system pressure limiting and unloading

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

• Steel and Mining Equipment — Pressure control for rolling mills and heavy-duty systems

Expert Maintenance Tips

1. Installation Guidelines

• Mounting surface must conform to ISO 6264-06-09 standards.

• 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.

• K4 suffix indicates without mating connector — users must separately select a compatible 3-pin DIN connector.

2. Hydraulic Fluid Cleanliness

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

• Seal material: NBR.

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

3. Pressure Setting Adjustment

• Factory pressure setting for DBW10B2-5X/100-6EG24NK4 is 100 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

• DBW10B2-5X/100-6EG24NK4 uses 24V DC supply.

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

• Ensure the connector is fully locked to maintain IP65 protection.

5. 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.

6. 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.

• Periodically check the pilot stage orifice for blockage (DBW series valves feature a damping orifice that affects dynamic response characteristics).