DFA-02-2B2 DOFLUID Solenoid Valve 350 Bar

Product Overview

The DOFLUID DFA-02-2B2-DC24V-35C belongs to the DFA/B-02 family of wet-pin solenoid directional valves for industrial hydraulic flow-direction control.

DOFLUID’s official product information identifies DFA/B-02/03 as wet solenoid directional valves and specifies a family maximum working pressure of 35 MPa (350 bar). The manufacturer also states that the immersed armature design supports stable and quiet operation under high-pressure and high-frequency conditions, while dual return flow passages help reduce return-line pressure loss and temperature rise.

The supplied product title contains several different spool configurations:

• DFA-02-2B2
• DFA-02-2B3
• DFA-02-2D2
• DFA-02-2D3

along with multiple electrical versions such as 24 VDC, 110 VAC and 220 VAC.

These spool configurations are not simply different coil-voltage versions. Published data show, for example, that the 2B3 configuration has distinct P-A/B-T flow states and a published maximum flow of 65 L/min, while a published 2B2 configuration is rated at approximately 80 L/min.

For genuine OEM replacement, the complete configuration must therefore be matched:

Series + Size + Spool + Coil Voltage + Connection + Hydraulic Rating

Technical Specifications

DFA-02-2B2-DC24V-35C

• Model: DFA-02-2B2-DC24V-35C
• Brand: DOFLUID
• Product Type: Wet-pin solenoid directional valve
• Actuation: Direct electromagnetic directional control
• Series: DFA-02
• Nominal Size: 02 / NG6 / CETOP 03 class
• Spool: 2B2
• Position Configuration: 2-position directional configuration
• Coil: DC24V
• Nominal Coil Voltage: 24 V DC
• Maximum Working Pressure: 35 MPa / 350 bar
• Published Flow Reference: approximately 80 L/min for the DFA/DFB-02-2B2 configuration
• Maximum Back Pressure Reference: 21 MPa / 210 bar, subject to spool-specific limitations
• Mounting: Subplate mounting
• Solenoid Construction: Wet-pin / immersed armature
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: No separate peak-pressure rating is specified; maximum working pressure is the applicable engineering limit
• Weight: No sufficiently verified official single-part weight is stated for this complete DC24V-35C configuration.

DFA-02-2B3-DC24V-35C

• Model: DFA-02-2B3-DC24V-35C
• Brand: DOFLUID
• Product Type: Direct-operated solenoid directional valve
• Series: DFA-02
• Nominal Size: 02 / NG6 / CETOP 03
• Spool: 2B3
• Position Configuration: 2-position
• Actuation: Direct solenoid
• Coil: DC24V
• Maximum Working Pressure: 350 bar
• Published Maximum Flow: 65 L/min
• Flow States: P→A and B→T in the relaxed state; P→B and A→T when energized
• Electrical Connection: DIN 43650 / ISO 4400 type, with published LED connector configuration
• Maximum Back Pressure: 210 bar
• Mounting: Subplate mounting
• Interface: CETOP 03 / NG6
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: No separate peak-pressure rating specified
• Weight: Exact weight for the complete configuration is not sufficiently verified.

DFA-02-2D2-DC24V-35C

• Model: DFA-02-2D2-DC24V-35C
• Brand: DOFLUID
• Product Type: Direct-operated solenoid directional valve
• Series: DFA-02
• Nominal Size: 02 / NG6 / CETOP 03
• Spool: 2D2
• Actuation: Direct electromagnetic control
• Coil: DC24V
• Maximum Working Pressure: 35 MPa / 350 bar at family level
• Maximum Flow: Not reliably verified for the exact complete configuration in currently accessible public documentation
• Back Pressure: Must be checked against the specific 2D2 spool configuration
• Mounting Interface: NG6 / CETOP 03 class
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: Not independently specified
• Weight: Not reliably verified.

DFA-02-2D3-DC24V-35C

• Model: DFA-02-2D3-DC24V-35C
• Brand: DOFLUID
• Product Type: Direct-operated solenoid directional valve
• Series: DFA-02
• Nominal Size: 02 / NG6 / CETOP 03
• Spool: 2D3
• Actuation: Direct electromagnetic control
• Coil: DC24V
• Maximum Working Pressure: 35 MPa / 350 bar at family level
• Maximum Flow: Not reliably verified for the exact complete DC24V-35C configuration
• Back Pressure: Requires verification for the 2D3 spool
• Mounting Interface: NG6 / CETOP 03 class
• Displacement: Not applicable
• Maximum Speed: Not applicable
• Peak Pressure: No separate official peak-pressure value
• Weight: Not reliably verified.

Common DFA/B Engineering Data

• Series: DFA/B-02 / DFA/B-03
• Valve Type: Wet-pin solenoid directional valve
• Nominal Sizes: 02 / 03
• Maximum Working Pressure: 35 MPa / 350 bar
• Family Maximum Flow Capacity: Up to 160 L/min
• Family Maximum Back-Pressure Reference: 21 MPa / 210 bar, subject to spool-specific limits
• Recommended Fluid Temperature: +5 to +60 °C
• Recommended Viscosity: 15 to 310 cSt
• Recommended Fluids: Petroleum-based mineral oils, phosphate/polyol ester hydraulic fluids and water-glycol fluids, subject to configuration and seal compatibility
• Contamination Control: NAS 1638-12 or cleaner, with 25 μm or finer filtration recommended
• Electrical Options: AC, DC and RAC rectifier-type configurations
• Electrical Connections: Terminal box, DIN plug and lead-wire configurations
• Displacement: Not applicable
• Maximum Rotational Speed: Not applicable.

Key Technical Advantages

1. Wet-pin solenoid construction

DOFLUID specifically highlights the immersed armature design of the DFA/B family.

The wet-pin architecture allows the moving magnetic component to operate within the hydraulic environment and supports stable operation at high pressure and high switching frequency. DOFLUID also identifies quiet operation and longer service life as benefits of this configuration.

2. 35 MPa high-pressure capability

The DFA/B-02/03 family is rated for up to:

35 MPa = 350 bar = 5,076 psi

This makes the valve suitable for demanding industrial hydraulic circuits rather than only low-pressure auxiliary systems.

3. Multiple spool functions

The DFA/B platform offers multiple two-position and three-position spool configurations.

In the configurations covered here, 2B2, 2B3, 2D2 and 2D3 represent different hydraulic functions. The complete spool code must therefore remain part of the replacement specification.

4. High-flow capability and return-flow optimization

DOFLUID specifies a family maximum flow capacity of 160 L/min and specifically highlights its dual return-flow passage design for reducing return-line pressure drop and thermal rise.

This is beneficial in high-cycle hydraulic systems where unnecessary return-side pressure losses can increase hydraulic power consumption.

5. Different flow capabilities by spool configuration

Published data show that maximum flow is spool-dependent:

• 2B2: approximately 80 L/min in published DFA/DFB-02 data
• 2B3: 65 L/min in published DFA-02 data.

Therefore, the flow rating should always be associated with the exact spool code.

6. Multiple coil and connector configurations

The official DOFLUID documentation lists:

• terminal-box coils
• DIN plug coils
• lead-wire coils
• AC coils
• DC coils
• RAC rectifier-type coils.

This enables the DFA/B platform to fit different industrial control architectures.

7. RAC coils for reduced AC switching stress

DOFLUID describes its RAC AC/DC rectifier coil as a way to reduce voltage rise during AC-to-DC rectification, lower operating noise and extend relay-contact life. It can also reduce coil heating during long-term operation.

This can be useful in legacy machinery using conventional relay-based solenoid control.

8. Optional hydraulic cushioning

DOFLUID also offers an S-option hydraulic cushioning configuration.

The manufacturer explains that this option slows spool transition to reduce switching impact, while also noting that the low-impact function does not operate normally until the return passage has been properly filled with hydraulic fluid.

9. Suitable for OEM replacement and interchangeability

The standardized NG6/CETOP 03 architecture is suitable for replacement of existing industrial hydraulic valves and manifold-mounted systems.

However, genuine Interchangeability requires matching:

• spool function
• mounting interface
• P/A/B/T flow paths
• coil voltage
• electrical connection
• pressure rating
• actual flow capacity
• return back pressure
• sealing and fluid compatibility

Our replacement engineering can reproduce the required DOFLUID DFA/B interface and hydraulic function and validate each unit through 100% simulated operating-condition testing.

Application Areas

DFA-02-2B2

Typical applications include:

• Industrial hydraulic power units
• Hydraulic clamping systems
• Machine-tool auxiliary circuits
• Injection-molding auxiliary hydraulics
• Automated hydraulic actuators
• Hydraulic lifting mechanisms
• OEM compact hydraulic stations

Published 2B2 data indicate approximately 80 L/min flow capability, making it suitable for medium-flow directional-control applications.

DFA-02-2B3

Typical applications include:

• Hydraulic actuator extension/retraction
• Machine-tool hydraulics
• Industrial automation
• Clamping and releasing mechanisms
• Compact hydraulic power units
• Material-handling equipment
• Injection and forming auxiliary circuits

Published data specify 65 L/min and clearly define the two switching flow states.

DFA-02-2D2 / 2D3

Because the exact standalone flow and spool-specific pressure data are not sufficiently verified in the currently accessible public records, these variants should be positioned primarily for:

• Industrial directional control
• OEM replacement
• Hydraulic equipment maintenance
• Hydraulic manifolds
• Automated hydraulic actuators

The final choice should be confirmed against the original nameplate and hydraulic schematic.

Expert Maintenance Tips

1. Preserve the complete spool code

Do not purchase only:

DFA-02

Specify the complete configuration, such as:

DFA-02-2B2-DC24V-35C

or the applicable 2B3 / 2D2 / 2D3 configuration.

The spool code defines the hydraulic switching function.

2. Match DC24V, AC110V and AC220V correctly

DOFLUID offers multiple electrical configurations.

Published records include configurations such as:

• DFA/DFB-02-2B2-DC24V-35C
• DFB-02-2B2-A110V-35C
• DFB-02-2B2-A220V-35C.

The coil voltage and AC/DC type must be matched before replacement.

3. Do not treat 350 bar as an unrestricted operating point

The 35 MPa figure is a maximum working-pressure rating.

Actual selection must also consider:

• flow rate
• pressure drop
• spool type
• T-port back pressure
• hydraulic-fluid temperature

4. Check return-line back pressure

DOFLUID explicitly warns that allowable return pressure may decrease depending on the spool type. The family documentation gives 21 MPa as a reference while requiring verification for the specific spool.

Dynamic T-line pressure should therefore be measured in multi-valve return systems.

5. Maintain hydraulic cleanliness

DOFLUID recommends contamination control at NAS 1638-12 or better and filtration of 25 μm or finer.

Contamination can cause:

• delayed switching
• incomplete spool movement
• abnormal leakage
• increased pressure drop

6. Avoid incorrect dry operation of wet-pin solenoids

The wet-pin construction depends on the correct hydraulic environment.

For hydraulic-cushioning configurations, DOFLUID specifically notes that the low-impact function cannot operate normally until the return path has been filled with hydraulic fluid.

7. De-energize AC coils before removal

DOFLUID warns that an AC solenoid coil should not be energized when the moving armature is not installed, because the coil can burn out.

This should be treated as a mandatory maintenance procedure.

8. Perform complete functional validation after replacement

Recommended tests include:

• coil-voltage verification
• solenoid switching
• spool-function verification
• P→A / P→B flow checks
• A/B→T return checks
• operating-pressure testing
• flow measurement
• T-port back-pressure measurement
• repeated switching
• thermal stabilization

For OEM replacement units, 100% simulated operating-condition testing should be completed before shipment to validate dimensional compatibility, electrical compatibility, spool function and hydraulic performance.