A. 4WE6D6X/EG24N9K4 — R900561274

Product Overview

The Bosch Rexroth 4WE6D6X/EG24N9K4, material number R900561274, is a direct-operated solenoid directional spool valve for industrial hydraulic flow-direction control.

Bosch Rexroth’s official Interactive Catalog directly identifies this exact configuration as a WE directional valve with wet-pin solenoids, nominal size 6, D spool, 6X component series, spring return, 24 V DC wet-pin solenoid, concealed N9 manual override and K4 electrical connector. The official catalog specifies approximately 80 L/min maximum flow capacity and 350 bar maximum operating pressure for the size platform.

The corresponding official CAD drawing is also identified as R900561274 / 4WE 6 D6X/EG24N9K4.

Technical Specifications

• Model: 4WE6D6X/EG24N9K4
• Material Number: R900561274
• Manufacturer: Bosch Rexroth
• Product Type: Direct-operated solenoid directional spool valve
• Nominal Size: NG6 / Size 6
• Ports: 4
• Spool Symbol: D
• Component Series: 6X
• Switching Positions: 2
• Spring Return: Yes
• Solenoid: High-performance wet-pin solenoid
• Solenoid Configuration: Single solenoid
• Voltage: 24 V DC
• Manual Override: N9, concealed manual override
• Electrical Connection: K4, DIN EN 175301-803
• Mounting: Subplate mounting
• Mounting Standard: DIN 24340 Form A / ISO 4401 / CETOP-RP 121-H
• CETOP Class: CETOP 03 / D03
• Maximum Operating Pressure: 350 bar
• Maximum Series Flow: Approximately 80 L/min
• Seal Material: NBR
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: No separate peak-pressure rating is defined; engineering selection should use the specified 350 bar maximum operating pressure
• Weight: No official single-part net weight is currently published in the Bosch Rexroth Interactive Catalog for this exact configuration. Third-party sales records provide differing shipping-weight values and are not treated as official net weight.

Key Technical Advantages

1. Direct solenoid actuation

The main spool is actuated directly by the solenoid without a separate hydraulic pilot stage.

This keeps the architecture compact and is well suited to NG6/CETOP 03 directional-control circuits.

2. 350 bar pressure capability

The official Bosch Rexroth catalog specifies 350 bar maximum operating pressure for the configuration.

3. Approximately 80 L/min flow platform

The Rexroth Interactive Catalog specifies approximately 80 L/min maximum flow for this size platform.

The actual application flow should nevertheless be verified against spool-specific pressure-drop characteristics.

4. Wet-pin removable-coil architecture

The high-performance wet-pin solenoid uses a removable coil.

This provides practical field-service benefits and supports repeatable electromagnetic actuation.

5. Concealed manual override

The N9 manual override provides a practical means of manually checking valve operation during commissioning and fault diagnosis.

6. Standard CETOP 03 interface

The ISO 4401 / CETOP 03 mounting pattern facilitates replacement in existing hydraulic manifolds and subplates.

7. NBR sealing and established hydraulic-fluid compatibility

The official catalog identifies NBR seals and approved hydraulic-fluid combinations for the WE platform.

8. OEM replacement capability

For R900561274, true interchangeability requires matching:

• D spool
• 2-position spring return
• 24 V DC solenoid
• N9 manual override
• K4 connector
• NBR seals
• 350 bar operating pressure
• actual flow and pressure-drop requirements

Our replacement engineering can reproduce the required interfaces and hydraulic function and validate each unit through 100% simulated operating-condition testing.

Application Areas

Typical applications include:

• Industrial hydraulic power units
• Hydraulic presses
• Machine tools
• Injection-molding auxiliary circuits
• Hydraulic clamping systems
• Automated actuators
• Lifting systems
• Metalworking machinery
• OEM hydraulic manifolds
• Legacy Rexroth equipment

Expert Maintenance Tips

• Verify the D spool before ordering a replacement.
• Confirm that the electrical system is 24 V DC.
• Keep the ISO 4401/CETOP 03 mounting surface clean.
• Use the N9 manual override for functional diagnosis when required.
• Control hydraulic contamination to prevent spool sticking.
• After replacement, verify P/A/B/T flow paths, pressure, pressure drop and repeated switching.

B. 4WEH16D7X/6EG24N9ETK4/B10 — R900924874

Product Overview

The Bosch Rexroth 4WEH16D7X/6EG24N9ETK4/B10, material number R900924874, is a pilot-operated electro-hydraulic directional spool valve for high-flow industrial hydraulic systems.

The official Bosch Rexroth replacement/type-code documentation directly links R900924874 to this exact 4WEH16 D7X configuration. The WEH family is documented under RE 24751.

Unlike the direct-operated 4WE6, the 4WEH16 uses a two-stage pilot-operated architecture in which the pilot valve hydraulically controls the main spool.

The complete configuration includes:

• NG16 main valve
• D spool
• 7X component series
• 6E high-performance pilot solenoid
• 24 V DC
• N9 concealed manual override
• ET internal pilot supply and return
• K4 DIN EN 175301-803 connector
• B10 Ø1.0 mm throttle insert.

An important engineering point is that this model does not use the H prefix. The standard configuration is therefore treated at the published 280 bar operating-pressure level rather than being automatically promoted to the 350 bar H-version rating.

Technical Specifications

• Model: 4WEH16D7X/6EG24N9ETK4/B10
• Material Number: R900924874
• Manufacturer: Bosch Rexroth
• Product Type: Pilot-operated electro-hydraulic directional spool valve
• Nominal Size: NG16 / Size 16
• Ports: 4
• Spool Symbol: D
• Component Series: 7X
• Actuation: Hydraulic pilot control
• Pilot Solenoid: 6E high-performance wet-pin solenoid
• Supply Voltage: 24 V DC
• Manual Override: N9 concealed manual override
• Pilot Supply: Internal
• Pilot Return: Internal
• Throttle Insert: B10, Ø1.0 mm
• Electrical Connection: K4, DIN EN 175301-803
• Mounting: Subplate mounting
• Mounting Interface: ISO 4401-07-07-0-05
• CETOP Class: CETOP 07 / D07
• Maximum Operating Pressure: 280 bar for the standard non-H configuration
• Maximum Flow: 300 L/min for the published NG16 D-spool operating limit
• Minimum Internal Pilot Pressure: 14 bar
• Maximum Pilot Pressure: 250 bar
• Pilot Flow Reference: approximately 35 L/min for shortest switching-time conditions
• Hydraulic Fluid Temperature, NBR: -20 to +80 °C
• Ambient Temperature: -20 to +50 °C
• Permitted Viscosity: 2.8 to 500 mm²/s
• Maximum Fluid Contamination: ISO 4406 Class 20/18/15
• Seal Material: NBR
• Approximate Weight: approximately 9.42 kg in exact-part commercial records; treated as a configuration reference rather than a universal WEH16 weight.
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: No separate peak-pressure rating is defined; engineering selection should use the applicable maximum operating pressure for the exact configuration.

Key Technical Advantages

1. Two-stage pilot-operated architecture

The pilot valve controls the main NG16 spool, allowing a relatively small electrical pilot stage to command a much larger main hydraulic flow.

This makes the architecture appropriate for high-flow industrial systems.

2. 300 L/min NG16 flow capability

Published configuration data specify up to 300 L/min for the NG16 D-spool arrangement.

Actual system sizing should still be based on pressure drop, flow rate, oil temperature and the real operating point.

3. ET internal pilot circuit

The ET configuration uses internal pilot-oil supply and internal pilot-oil return.

This reduces external pilot piping and simplifies manifold integration.

4. B10 Ø1.0 mm throttle insert

The B10 insert is an important part of the pilot circuit.

Rexroth documentation identifies the throttle insert as a means of controlling pilot flow and avoiding inadmissible pressure peaks in the pilot valve circuit.

5. 7X series compatibility

The 7X configuration forms part of the WEH NG16 platform and is directly associated with R900924874 in Bosch Rexroth’s model/reference documentation.

6. Standard 24 V DC and K4 connection

The G24/K4 combination uses a conventional 24 V DC solenoid and DIN EN 175301-803 connector architecture.

7. High-flow control with controlled pilot dynamics

The pilot-operated structure allows large main-spool hydraulic power to be controlled through a compact electrical pilot stage.

Correct pilot pressure, B10 sizing and return conditions are therefore essential for predictable switching behavior.

8. OEM replacement engineering

For R900924874, true interchangeability requires matching:

• NG16 / CETOP 07 interface
• D spool
• 24 V DC pilot solenoid
• N9 manual override
• ET internal pilot circuit
• K4 connector
• B10 throttle insert
• NBR seals
• 280 bar pressure configuration
• actual 300 L/min operating requirement

Our replacement engineering can reproduce these mechanical and hydraulic characteristics and apply 100% simulated operating-condition testing before shipment.

Application Areas

Typical applications include:

• Hydraulic presses
• Injection and forming machines
• Forging equipment
• Metal-forming machinery
• Steel and metallurgical hydraulic systems
• Large hydraulic power units
• High-flow actuator systems
• Industrial automation hydraulic stations
• Heavy-duty machine tools
• OEM multi-valve hydraulic systems

Expert Maintenance Tips

• Confirm the valve is the standard non-H configuration before using the 280 bar rating.
• Verify that internal pilot pressure is sufficient; published NG16 data specify approximately 14 bar minimum under the applicable internal-pilot conditions.
• Never remove or arbitrarily resize the B10 Ø1.0 mm throttle insert.
• Confirm the ET internal pilot supply/return configuration.
• Monitor T-port return pressure independently from main-port pressure.
• Maintain hydraulic cleanliness at ISO 4406 Class 20/18/15 or better.
• After replacement, perform pressure, flow, spool-shifting, dynamic and thermal tests.