DBW20A2-5X/100Y6EG24NK4 | Rexroth Solenoid Relief Valve 350bar 650L/min

Product Overview

The DBW20A2-5X/100Y6EG24NK4 (Material Number R900706341) is a classic model in the Bosch Rexroth DBW series of pilot-operated solenoid relief valves. 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 DBW20A2-5X/100Y6EG24NK4 features A2 spool symbol, 5X component series (50–59), a maximum pressure setting of 100 bar, a maximum operating pressure of 350 bar, and a maximum flow rate of 650 L/min. It is equipped with NBR seals, compatible with HL, HLP, HLPD, HVLP, HVLPD, and HFC hydraulic fluids. The valve features subplate mounting with porting patterns conforming to ISO 6264 standards. The electrical connector conforms to EN standards. Weight is approximately 5.36 kg.

Model Code Breakdown (DBW20A2-5X/100Y6EG24NK4):

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

• 20: Nominal Size NG20 (NG25 interface)

• A2: Spool symbol and configuration (A type)

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

• 100: Pressure setting (100 bar)

• Y: Pilot oil supply configuration — internal supply, external return via Y port

• 6E: With wet-type solenoid

• G24: DC 24V supply (G = DC)

• N: NBR seals

• K4: Without mating connector

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.

Technical Specifications 

• Model: DBW20A2-5X/100Y6EG24NK4

• Material Number: R900706341

• Brand: BOSCH REXROTH

• Series: DBW Series, 5X Component Series

• Product Type: Pilot-operated Solenoid Relief Valve

• Spool Symbol: A2 type

• Nominal Size: NG25 (DN25)

• Mounting Standard: ISO 6264-08-13

• Mounting Type: Subplate Mounting

• Maximum Operating Pressure: 350 bar (5075 psi) 

• Maximum Flow Rate: 650 L/min (172 GPM) 

• Pressure Setting Range: 4–100 bar

• Maximum Pressure Setting: 100 bar (1450 psi) 

• Coil Voltage: 24V DC

• Seal Material: NBR

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

• Adjustment Types: Multiple (rotary knob, sleeve with hexagon and protective cap, lockable rotary knob with scale, rotary knob with scale)

• Weight: 5.36 kg

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

Key Technical Advantages

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

The DBW20A2-5X/100Y6EG24NK4 features pilot-operated construction—the main valve is controlled by a pilot control valve, with the pilot spool controlling the main spool action. Compared to direct-acting relief valves, the pilot-operated design delivers superior pressure/flow stability, lower hysteresis, and more precise pressure control. Maximum flow reaches 650 L/min with a maximum operating pressure of 350 bar.

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. A Spool Symbol — Adapts to Specific System Requirements

The DBW20A2-5X/100Y6EG24NK4 features A spool symbol. The DBW series offers both A type and B type configurations, with A type adapting to specific hydraulic circuit design requirements.

4. Wide Pressure Setting Range — 4–100 bar with Multiple Adjustment Types

The DBW20A2-5X/100Y6EG24NK4 covers a pressure setting range of 4–100 bar. The DBW series offers 5 pressure ratings. 4 adjustment types are available: rotary knob, sleeve with hexagon and protective cap, lockable rotary knob with scale, and rotary knob with scale.

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, meeting diverse industrial application requirements.

6. Optional Switching Shock Damping — Reduced System Noise

Optional switching shock damping is available. By delaying the opening via a sandwich plate design, it effectively mitigates pressure peaks and acoustic decompression shocks in the return line. The R12 nozzle (Ø1.2 mm) is recommended for optimal damping. This feature is particularly beneficial for reducing system noise and enhancing operational stability.

7. International Standard Compliance for Global Interchangeability

Mounting conforms to ISO 6264-08-13 (NG25) standards. The DBW series offers complete interchangeability with globally adopted interfaces. Subplate mounting facilitates system integration and maintenance.

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

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

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

Expert Maintenance Tips

1. Installation Guidelines

• DBW20A2-5X/100Y6EG24NK4 mounting must conform to ISO 6264-08-13 (NG25) 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

• DBW20A2-5X/100Y6EG24NK4 setting range: 4–100 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

• DBW20A2-5X/100Y6EG24NK4 uses 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. 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. Switching Shock Damping Configuration (If Equipped)

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

• The R12 (Ø1.2 mm) nozzle is recommended for optimal performance.

• Refer to Rexroth technical documentation for damping characteristic adjustments.

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.

• DBW valves feature pilot-operated poppet construction—blockage of the pilot stage orifice is a common cause of compromised dynamic response.