Product Overview
The DBW10B-1-50B/3156CG24N9Z5L and DBW10A-2-50/200-6AG24Z5L are classic models in the Bosch Rexroth DBW series of pilot-operated solenoid relief valves, NG10 (CETOP 5 / NFPA D05) size. The DBW series adds a solenoid directional valve to the DB series relief valve, enabling system pressure limiting and remote solenoid-actuated unloading.
The DBW series 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. Both models feature B spool symbol (P→T flow path) with a maximum operating pressure of 315 bar.
Key differences between the two models:
DBW10B-1-50B/3156CG24N9Z5L: Maximum pressure setting 315 bar, nominal size 10 mm, adjustment range 5–315 bar
DBW10A-2-50/200-6AG24Z5L: Maximum pressure setting 200 bar, with Z5L option code
Both models have a maximum operating pressure of 315 bar and a maximum flow rate of 250 L/min.
As original Bosch Rexroth pilot-operated solenoid relief valves, these products offer complete interchangeability within the same series and size, requiring no modifications to mounting interfaces or piping layouts.
Technical Specifications
DBW10B-1-50B/3156CG24N9Z5L Specifications:
Model: DBW10B-1-50B/3156CG24N9Z5L
Brand: BOSCH REXROTH
Series: DBW Series
Product Type: Pilot-operated Solenoid Relief Valve
Spool Symbol: B type (P→T)
Nominal Size: NG10 (10 mm)
Mounting Standard: ISO 4401-05 / CETOP 5
Mounting Type: Subplate Mounting
Maximum Operating Pressure: 315 bar (31.5 MPa)
Adjustment Range: 5–315 bar (5~31.5 MPa)
Rated Flow: 40–60 L/min (depending on system conditions)
Maximum Flow Rate: 250 L/min
Coil Voltage: DC24V
Protection Class: IP65 (Z5L coil)
Seal Material: NBR / FKM (depending on version)
Hydraulic Fluids: Mineral hydraulic oil (recommended viscosity 10–400 cSt)
Temperature Range: -20°C to +70°C
Weight: Approx. 2.8 kg
DBW10A-2-50/200-6AG24Z5L Specifications:
Model: DBW10A-2-50/200-6AG24Z5L
Material Number: R900523062
Brand: BOSCH REXROTH
Series: DBW Series
Product Type: Pilot-operated Solenoid Relief Valve
Spool Symbol: B type (P→T)
Nominal Size: NG10 (10 mm)
Mounting Standard: ISO 4401-05 / CETOP 5
Mounting Type: Subplate Mounting
Maximum Operating Pressure: 315 bar (31.5 MPa)
Maximum Pressure Setting: 200 bar (20 MPa)
Adjustment Range: 3–200 bar
Maximum Flow Rate: 250 L/min
Coil Voltage: DC24V
Option Code: Z5L
Protection Class: IP65
Seal Material: NBR (standard)
Hydraulic Fluids: Mineral hydraulic oil
Temperature Range: -20°C to +70°C
Weight: Approx. 2.8 kg
Key Technical Advantages
1. Pilot-Operated Design — High-Pressure High-Flow with Precise Control
The DBW10 series 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 250 L/min with a maximum operating pressure of 315 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. 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. The B configuration is ideal for applications requiring direct unloading to tank.
4. Multiple Pressure Grades with Various Adjustment Types
The DBW10 series offers multiple pressure grades. DBW10B-1-50B/3156CG24N9Z5L provides an adjustment range of 5–315 bar. DBW10A-2-50/200-6AG24Z5L provides a maximum setting of 200 bar. Pressure adjustment is performed via the adjustment element on the pilot valve.
5. IP65 Protection with Z5L Coil Option
Equipped with Z5L coil, offering IP65 protection with oil-resistant and waterproof construction. Suitable for demanding industrial environments with moisture and dust.
6. International Standard Compliance for Global Interchangeability
Mounting conforms to ISO 4401-05 and CETOP 5 standards. The DBW series offers complete interchangeability with globally adopted NG10 size interfaces.
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 4401-05 and CETOP 5 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.
2. Hydraulic Fluid Cleanliness
Compatible fluids: Mineral hydraulic oil (recommended viscosity 10–400 cSt).
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
DBW10B-1-50B/3156CG24N9Z5L adjustment range: 5–315 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 DC24V supply.
Z5L coil offers IP65 protection with oil-resistant and waterproof construction.
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. 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.
DB/DBW valves feature cast internal flow passages for excellent flow capacity, simple construction, and good opening/closing characteristics.
