DB20-1-5X/315 Rexroth Pilot Operated Relief Valve 315 bar 500 L/min

I. DB20-1-5X/315 Pilot-Operated Relief Valve

Product Overview

The DB20-1-5X/315 (Material No. R900587346) is a classic pilot-operated pressure relief valve from Bosch Rexroth’s DB series, sized NG20 with subplate mounting conforming to ISO 6264-06-09 (NG10/NG20) .

The DB series pilot-operated relief valve consists of a main valve (with main spool insert) and a pilot control valve (with pressure adjustment element) . When the pressure at port P exceeds the spring setting of the pilot valve, the pilot ball opens, allowing fluid from the spring chamber of the main spool to flow to tank—the main spool then opens, and fluid flows from port P to port T, limiting system pressure to the set value .

The defining feature of this model (DB20-1-5X/315) is the “-1” code—indicating the valve is equipped with unloading or switching to a second pressure rating via port X . Multiple adjustment options (rotary knob, hexagon with protective cap, lockable rotary knob with scale, etc.) are available to suit different application requirements .

As a direct replacement solution for the Bosch Rexroth DB series, this product strictly complies with Rexroth RE 25802 technical standards  and offers complete interchangeability—direct drop-in replacement without any modification to mounting dimensions or piping connections. Every unit undergoes 100% simulated duty cycle testing prior to shipment, ensuring performance reliability and long-term operational stability under actual working conditions.

Technical Specifications

• Model: DB20-1-5X/315

• Material Number: R900587346

• Product Type: Pilot-operated Pressure Relief Valve

• Nominal Size: 20 (NG20)

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

• Mounting Type: Subplate Mounting

• Porting Pattern Standard: ISO 6264-06-09

• Maximum Operating Pressure: 350 bar 

• Pressure Setting Range: Up to 315 bar

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

• Spool Symbol: P → T

• Seal Material: NBR 

• Hydraulic Fluid Compatibility: HL, HLP, HLPD, HVLP, HVLPD, HFC 

• Adjustment Options: Rotary knob / Hexagon with protective cap / Lockable rotary knob with scale / Rotary knob with scale 

• Corrosion Protection: Salt spray test per ISO 9227 

• Weight: Approx. 2.6 – 4.4 kg (configuration dependent) 

Key Technical Advantages

1. Pilot-Operated Design – High Flow & High Accuracy
The DB20 series features a pilot-operated design where the pilot valve precisely controls the main valve cracking pressure . Compared to direct-operated relief valves, the pilot-operated design maintains extremely low pressure overshoot and superior regulation accuracy even under high-flow conditions.

2. Port X Remote Control – Unloading & Multi-Pressure Switching
The “-1” code indicates an integrated port X for remote pressure setting, system unloading, or multi-stage pressure switching via external pilot valves . This provides exceptional flexibility for integrated control and energy-saving operation in complex hydraulic systems.

3. Modular Adjustment Elements – Flexible Configuration
Four adjustment options are available: rotary knob, hexagon with protective cap, lockable rotary knob with scale, and rotary knob with scale . Users can select the most appropriate adjustment type based on anti-tamper requirements, setting accuracy needs, and on-site operating preferences .

4. Optimized Flow Path & Corrosion Protection
The internal flow paths are optimized to deliver up to 500 L/min in the NG20 envelope . The valve features corrosion-protected design with 240-hour salt spray testing per EN ISO 9227 , ensuring long-term reliability in humid and corrosive environments .

5. Broad Fluid Compatibility
NBR seals are compatible with HL, HLP, HLPD, HVLP, HVLPD mineral-oil-based hydraulic fluids and HFC water-glycol fire-resistant fluids .

Application Areas

• Large Hydraulic Power Units: Main system relief valve for pressure limiting

• Injection Molding Machinery: Multi-stage pressure control and overpressure protection

• Hydraulic Presses & Die-Casting: Pressure limiting and unloading in high-flow systems

• Metallurgical Equipment: Pressure control and safety protection in rolling mill hydraulics

• Test Rigs: Precise pressure setting for high-flow hydraulic test systems

• Marine & Offshore: Pressure limiting and remote control in hydraulic systems

Expert Maintenance Tips

1. Mounting Surface Verification
DB20-1-5X/315 conforms to ISO 6264-06-09 . Thoroughly clean the mounting surface prior to installation and inspect O-ring seals—replace after every disassembly.

2. Port X Usage
Port X enables remote control and unloading . When using remote control, port X must be connected to an external pilot valve with pressure within allowable limits. If not used, port X must be securely plugged.

3. Installation Torque
Tighten mounting bolts in diagonal sequence over multiple passes to torque values specified in Rexroth RE 25802 .

4. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours:

• Verify cracking pressure matches set value

• Check port X connections for leakage

• Inspect adjustment mechanism for smooth operation

• Inspect O-ring seals for aging or damage

II. DBDS6K1X/315 Direct-Operated Relief Valve (Screw-in Cartridge)

Product Overview

The DBDS6K1X/315 (Material No. R900423725) is a direct-operated seat valve from Bosch Rexroth’s DBD series, sized NG6 with screw-in cartridge mounting .

The DBD series direct-operated relief valve consists of a sleeve, spring, poppet with damping piston, and adjustment element . Port P pressure acts directly on the poppet. When the pressure exceeds the spring setting, the poppet opens against the spring force, allowing flow from port P to port T—limiting system pressure to the set value. The damping piston effectively suppresses spool vibration for stable pressure regulation .

The DBDS series uses a poppet as the closing element (distinct from the ball-type DBDH series), delivering excellent sealing performance and fast response at the 315 bar pressure rating .

As a direct replacement solution for the Bosch Rexroth DBD series, this product strictly complies with Rexroth RE 25402 technical standards  and offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: DBDS6K1X/315

• Material Number: R900423725

• Product Type: Direct Operated Pressure Relief Valve

• Nominal Size: 6 (NG6)

• Component Series: 1X (series 10–19)

• Mounting Type: Screw-in Cartridge 

• Maximum Operating Pressure: 400 bar 

• Pressure Setting Range: Up to 315 bar 

• Maximum Flow Rate: 50 L/min 

• Spool Type: Poppet with damping piston 

• Seal Material: NBR 

• Hydraulic Fluid: HL, HLP per DIN 51524 

• Fluid Temperature Range: -20 °C to +80 °C (NBR seals) 

• Adjustment Element: Hexagon with protective cap / Rotary knob 

• Weight: Approx. 0.38 – 0.514 kg 

Key Technical Advantages

1. Direct-Acting Design – Extremely Fast Response
The DBDS6K1X/315 features a direct-acting design where system pressure acts directly on the poppet—no pilot stage delay . Response time is extremely short, making it ideal for applications with demanding pressure response requirements.

2. Poppet with Damping Piston – Stable & Vibration-Free
The poppet with damping piston design effectively suppresses vibration and noise during opening and closing , ensuring smooth pressure regulation and excellent repeatability.

3. Compact Screw-in Cartridge Design – High System Integration
The screw-in cartridge mounting allows direct installation into standard manifold cavities —no piping required, significantly reducing leak points and saving space.

4. Wide Temperature Range & Fluid Compatibility
Operating temperature range covers -20 °C to +80 °C , compatible with HL, HLP mineral-oil-based hydraulic fluids per DIN 51524 .

Application Areas

• Small Hydraulic Systems: Branch circuit or subsystem safety protection

• Pilot Control Circuits: Stable pilot pressure limiting

• Mobile Machinery: Overpressure protection for construction and agricultural equipment

• Machine Tools: Pressure limiting for tool feed, workholding, and auxiliary functions

• Test Equipment: Precise pressure setting for hydraulic test benches

Expert Maintenance Tips

1. Cavity Cleaning
Thoroughly clean the manifold cavity prior to installation. Inspect O-ring seals—replace after every disassembly .

2. Installation Torque
Use a torque wrench for cartridge installation. Over-torquing can cause valve body distortion or spool binding.

3. Pressure Setting
Turn adjustment element clockwise to increase pressure, counterclockwise to decrease . Calibrate under actual operating flow and temperature conditions and verify 2–3 times.

4. Scheduled Maintenance
Verify cracking pressure matches set value every 2,000 operating hours.

III. DBDS10P1X/315 Direct-Operated Relief Valve (Subplate Mounting)

Product Overview

The DBDS10P1X/315 (Material No. R900424158) is a large-size direct-operated seat valve from Bosch Rexroth’s DBD series, sized NG10 with subplate mounting .

Like the DBDS6K1X/315, the DBDS10P1X/315 uses a poppet as the closing element . Port P pressure acts directly on the poppet; when pressure exceeds the spring setting, the poppet opens and fluid flows from port P to port T. The P1X code indicates subplate mounting configuration with interface conforming to ISO 4401 .

The DBDS10P1X/315 features a maximum operating pressure of 630 bar , far exceeding the pressure rating of comparable direct-operated relief valves, making it ideal for ultra-high-pressure hydraulic systems.

As a direct replacement solution for the Bosch Rexroth DBD series, this product strictly complies with Rexroth RE 25402 technical standards  and offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: DBDS10P1X/315

• Material Number: R900424158

• Product Type: Direct Operated Pressure Relief Valve

• Nominal Size: 10 (NG10) 

• Component Series: 1X

• Mounting Type: Subplate Mounting 

• Maximum Operating Pressure: 630 bar 

• Pressure Setting Range: Up to 315 bar 

• Maximum Flow Rate: 120 L/min 

• Spool Type: Poppet 

• Seal Material: NBR 

• Adjustment Element: Hexagon with protective cap 

• Corrosion Protection: 240-hour salt spray test per EN ISO 9227 

• Weight: Approx. 3.681 – 3.75 kg 

Key Technical Advantages

1. Ultra-High Pressure Capability – 630 bar Rating
The DBDS10P1X/315 offers a maximum operating pressure of 630 bar , far exceeding comparable direct-operated relief valves—making it the preferred choice for ultra-high-pressure applications.

2. Direct-Acting Design – No Pilot Delay
The direct-acting design means system pressure acts directly on the poppet —no pilot stage delay, delivering extremely fast response essential for system safety in ultra-high-pressure applications.

3. Poppet Design – Extremely Low Leakage
The poppet creates a precision face-contact seal with the valve seat , ensuring extremely low internal leakage—critical for long-term pressure holding applications.

4. Enhanced Corrosion Protection
The valve features corrosion-protected design with 240-hour salt spray testing per EN ISO 9227 , ensuring long-term reliability in humid, marine, or corrosive environments.

5. Compact Subplate Mounting
Delivers 120 L/min flow capacity  in the NG10 envelope with compact mounting dimensions—direct integration into existing valve manifolds without additional piping.

Application Areas

• Ultra-High-Pressure Hydraulic Systems: Hydraulic tools, bolt tensioners, jacks

• Test Equipment: Precise pressure setting and protection for ultra-high-pressure test benches

• Injection Molding: Pressure limiting for high-pressure injection circuits

• Hydraulic Presses: Overpressure protection for high-pressure pressing systems

• Marine & Offshore: Safety protection for high-pressure hydraulic systems

• Special Industrial Applications: Systems requiring 630 bar ultra-high-pressure protection

Expert Maintenance Tips

1. Mounting Surface Verification
DBDS10P1X/315 conforms to ISO 4401 . Thoroughly clean the mounting surface and inspect O-ring seals—replace after every disassembly.

2. Installation Torque
Tighten mounting bolts in diagonal sequence over multiple passes to torque values specified in Rexroth RE 25402 .

3. Ultra-High-Pressure System Considerations
In 630 bar applications:

• System piping and fitting pressure ratings must match

• Mounting surface flatness and finish must meet standard requirements

• Install isolation valves upstream and downstream for safe maintenance

4. Scheduled Maintenance
Verify cracking pressure matches set value every 2,000 operating hours.

IV. DBDS20P1X/315 Direct-Operated Relief Valve (Subplate Mounting)

Product Overview

The DBDS20P1X/315 (Material No. R900424278) is the largest-size direct-operated seat valve from Bosch Rexroth’s DBD series, sized NG20 with subplate mounting conforming to ISO 6264 / NG20 (DIN 24340 Form A) .

The DBDS20P1X/315 uses a poppet as the closing element . Port P pressure acts directly on the poppet; when pressure exceeds the spring setting, the poppet opens and fluid flows from port P to port T . The P1X code indicates subplate mounting; the adjustment element is a hexagon socket setscrew with protective cap (adjustable via Allen key) .

DBDS20 is the highest-capacity model in the DBD series, with maximum flow up to 200–250 L/min. Combined with a maximum operating pressure of 630 bar, it delivers both high flow and ultra-high pressure capability—ideal for heavy-duty industrial hydraulic systems .

As a direct replacement solution for the Bosch Rexroth DBD series, this product strictly complies with Rexroth RE 25402 technical standards  and offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: DBDS20P1X/315

• Material Number: R900424278

• Product Type: Direct Operated Pressure Relief Valve 

• Nominal Size: 20 (NG20) 

• Mounting Type: Subplate Mounting 

• Porting Pattern Standard: ISO 6264 / NG20 (DIN 24340 Form A) 

• Maximum Operating Pressure (P-port) : 630 bar 

• Pressure Setting Range: Up to 315 bar 

• Maximum Flow Rate: Approx. 200 – 250 L/min 

• Spool Type: Poppet 

• Seal Material: NBR 

• Hydraulic Fluid: Mineral oil HL, HLP per DIN 51524; HFC (water-glycol); HLPD, HVLP, HVLPD 

• Fluid Temperature Range: -30 °C to +80 °C (NBR seals) 

• Viscosity Range: 10 – 800 mm²/s 

• Adjustment Element: Hexagon socket setscrew with protective cap 

• Body Material: Steel, zinc-plated 

• Weight: Approx. 8.0 kg 

Key Technical Advantages

1. High Flow Capacity – 200–250 L/min
DBDS20P1X/315 is the highest-capacity model in the DBD series, delivering up to 200–250 L/min—eliminating the need for parallel smaller valves in large hydraulic systems.

2. High Flow & Ultra-High Pressure Combined
Achieves 200–250 L/min flow while maintaining 630 bar maximum operating pressure . This combination of high flow and ultra-high pressure is extremely rare in direct-operated relief valves .

3. Direct-Acting Design – Fast Response at Extreme Conditions
Despite NG20 size and 250 L/min flow, DBDS20 remains direct-acting —system pressure acts directly on the poppet with no pilot delay. Fast response is critical for system safety in high-flow, ultra-high-pressure applications.

4. Wide Temperature & Viscosity Range
Fluid temperature range -30 °C to +80 °C, viscosity range 10 – 800 mm²/s—ensuring stable operation from cold starts to high-temperature running.

5. Robust Steel Body with Zinc Plating
The valve body is manufactured from steel with zinc plating , delivering superior mechanical strength and corrosion resistance for heavy-duty industrial environments.

Application Areas

• Large Industrial Hydraulic Systems: Main system relief or high-flow branch circuit safety protection

• Heavy Hydraulic Presses: Overpressure protection and pressure limiting for high-flow, high-pressure systems

• Metallurgical Equipment: Pressure control for rolling mills and continuous casting equipment

• Injection Molding: Pressure limiting for high-pressure injection circuits on large machines

• Marine & Offshore: Safety protection for large marine hydraulic systems

• Mining Equipment: Overpressure protection for heavy mining machinery hydraulics

Expert Maintenance Tips

1. Mounting Surface Verification
DBDS20P1X/315 conforms to ISO 6264 / NG20 . Thoroughly clean the mounting surface and inspect O-ring seals. Due to weight (approx. 8.0 kg) , use appropriate lifting equipment during installation.

2. Installation Torque
Tighten mounting bolts in diagonal sequence over multiple passes to torque values specified in Rexroth RE 25402 . Use a torque wrench for accurate torque application.

3. High-Flow System Considerations
In 200–250 L/min applications:

• Ensure adequate T-port return line sizing to prevent excessive back pressure

• Return filters must have sufficient flow capacity

• Install a pressure gauge at port T to monitor back pressure

4. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours:

• Verify cracking pressure matches set value

• Check for abnormal leakage or pressure drift

• Monitor T-port back pressure within allowable limits

• Inspect O-ring seals for aging or damage

V. DBW10B-5X/315 Pilot-Operated Solenoid Relief Valve

Product Overview

The DBW10B-5X/315 is a pilot-operated solenoid relief valve from Bosch Rexroth’s DBW series, sized NG10 with subplate mounting .

The DBW series is the solenoid-actuated extension of the DB series—integrating a solenoid directional valve into the pilot-operated relief valve to provide both pressure limiting and solenoid-actuated unloading . When the solenoid is de-energized, the valve functions as a standard pilot-operated relief valve. When the solenoid is energized, the pilot spring chamber is vented to tank through the solenoid valve, the main valve fully opens, and system pressure unloads to near zero .

The “B” code indicates B-type port configuration (P and T ports on the same side); “5X” indicates component series 50–59; “315” indicates maximum pressure setting of 315 bar . Solenoid voltage is typically 24 V DC depending on configuration .

As a direct replacement solution for the Bosch Rexroth DBW series, this product strictly complies with Rexroth RE 25802 technical standards  and offers complete interchangeability. Every unit undergoes 100% simulated duty cycle testing.

Technical Specifications

• Model: DBW10B-5X/315

• Product Type: Pilot-operated Solenoid Relief Valve 

• Nominal Size: 10 (NG10) 

• Component Series: 5X (series 50–59)

• Mounting Type: Subplate Mounting 

• Maximum Operating Pressure: 350 bar 

• Pressure Setting Range: Up to 315 bar

• Maximum Flow Rate: 250 L/min 

• Port Configuration: B-type (P and T ports on same side)

• Solenoid Voltage: 24 V DC (typical) 

• Solenoid Type: Wet-pin DC Solenoid 

• Seal Material: NBR

• Hydraulic Fluid: Mineral-oil-based hydraulic fluids

• Viscosity Range: 10 – 800 mm²/s 

• Weight: Approx. 4.05 kg (with solenoid) 

Key Technical Advantages

1. Solenoid Unloading – Energy-Saving Operation
DBW10B-5X/315 integrates a solenoid directional valve for solenoid-actuated unloading and pressure build-up . During standby, solenoid energization unloads the system to near-zero pressure—significantly reducing energy consumption and heat generation while extending pump service life.

2. Pilot-Operated Design – High Flow & High Accuracy
The pilot-operated design  delivers 250 L/min flow capacity in NG10  with excellent regulation accuracy and minimal pressure overshoot even under high-flow conditions.

3. Wet-Pin DC Solenoid – Long Life & High Reliability
The wet-pin DC solenoid  operates with the armature in oil—providing both lubrication and heat dissipation for extended service life. DC solenoids offer smooth switching, no inrush current, and low electromagnetic interference.

4. Modular Design – Flexible Configuration
DBW series offers multiple port configurations (A-type, B-type, etc.), multiple solenoid voltages (24 V DC, 110 V DC, 230 V AC, etc.), and multiple electrical connection options.

5. Compact Subplate Mounting
Delivers 250 L/min flow capacity  in the NG10 envelope with compact dimensions—direct integration into existing valve manifolds.

Application Areas

• Fixed Displacement Pump Unloading Circuits: Solenoid unloading during standby to reduce energy consumption and heating

• Injection Molding Machinery: Multi-stage pressure control and system unloading

• Hydraulic Presses: Unloading and pressure build-up control during rapid traverse

• Mobile Machinery: Energy-saving unloading during implement standby

• Industrial Hydraulic Systems: Remote pressure control and unloading for various industrial equipment

• Test Equipment: Rapid pressure build-up and unloading for hydraulic test benches

Expert Maintenance Tips

1. Mounting Surface Verification
DBW10B-5X/315 conforms to ISO 4401. Thoroughly clean the mounting surface and inspect O-ring seals—replace after every disassembly.

2. Solenoid Electrical Connection

• Verify supply voltage matches solenoid rating (typically 24 V DC) 

• DC solenoids are typically non-polarized (check specific model documentation)

• Use mating connector per DIN EN 175301-803 

• Use shielded cables to minimize electromagnetic interference

3. T-Port Back Pressure Limit
T-port back pressure limits depend on solenoid type—210 bar for DC solenoids, 160 bar for AC solenoids . Ensure return line design keeps T-port back pressure within allowable limits.

4. Manual Override
DBW series solenoids typically feature a manual override button —allowing valve actuation in case of solenoid failure or power loss. Exercise caution during operation to avoid high-pressure fluid spray.

5. Scheduled Maintenance
Perform preventive maintenance every 2,000 operating hours:

• Verify cracking pressure and unloading function

• Inspect solenoid coil resistance and insulation

• Check electrical connections for looseness, oxidation, or arcing damage

• Verify manual override functionality

• Inspect O-ring seals for aging or damage