4WRE 4WREE 6 E08 Series Hydraulic Proportional Directional Valve 4WREE 6 E08-22/G24K31/A1V-655

2. Product attributes
Based on the above analysis, the core attributes of this product are:Product Type: Electro-hydraulic proportional directional Valve (with integrated electronic amplifier)

Diameter specification: NG6

Valve core type: Zero-cover valve core (E08-22), used for high-precision control

Rated flow rate: approximately 22 L/min (when Δp=100 bar, sample confirmation is required)

Working pressure: The maximum is usually 315 bar or 350 bar

Power supply voltage: DC24V

Control signal: Usually ±10 VDC or 0/4-20 mA analog signal

Median function: It is necessary to check the sample according to “E”, and the common types are O type (all oil ports are closed) or Y type (A and B are connected to T).

3. How it works
Signal input: An external controller (such as a PLC) sends an analog control signal (for example, 0 to +10V or 4-20mA) to the integrated amplifier of the valve.

Signal processing and amplification: The electronic amplifier integrated on the valve receives this weak signal and amplifies it into a current signal proportional to the input signal, which is then output to the proportional electromagnet.

Electromagnetic force generation: When current passes through the coil of a proportional electromagnet, an electromagnetic force proportional to the magnitude of the current is generated.

Valve core movement: Electromagnetic force pushes the valve core to overcome the spring force and generate displacement. The larger the input signal, the greater the current, the stronger the electromagnetic force, and the greater the displacement of the valve core.

Throttling control: The displacement of the valve core determines the opening degree of the throttling window formed between its upper shoulder and the countersunk groove of the valve body. The larger the opening, the greater the flow area from P to A (or B) and from B (or A) to T.

Proportional output: Ultimately, the input electrical signal is linearly converted into a hydraulic output:

Control direction: The positive or negative input signal determines which electromagnet is energized, thereby controlling the direction of oil flow (oil entering from port A or Port B).

Control speed: The magnitude of the input signal determines the opening degree of the valve port, thereby precisely controlling the flow towards the actuator and further regulating its movement speed.

4. Characteristics
High precision and controllability: The zero-cover valve core and proportional control achieve unlimited, smooth and precise regulation of speed and direction.

Integrated amplifier: It eliminates the trouble of external amplifiers, simplifies wiring, enhances anti-interference ability, and is convenient for installation and replacement.

Energy conservation: Compared with servo valves, it has stronger anti-pollution ability and lower cost. Compared with on-off valves, it can eliminate hydraulic shock and save energy and reduce noise.

Standardization and modularization: The NG6 bore is an industrial standard and can be conveniently combined with superimposed valves (such as relief valves and pressure reducing valves) to build a compact hydraulic control unit.

Flutter signal: The built-in flutter signal (defined by A1V-655) can mask the static friction force of the valve core, prevent jamming, make the movement smoother and have higher resolution.

5. Installation and operation
Installation precautions

Base plate and connection: The valve is installed on a base plate that complies with the ISO 4401 standard. Ensure that the oil passage of the bottom plate is clean and that the connecting bolts are tightened in accordance with the specified torque and sequence.

Oil cleanliness: Of vital importance! The proportional valve has extremely high requirements for the cleanliness of the oil. It is recommended to reach NAS 1638 grade 7 or ISO 4406 16/13/10. A high-pressure filter (β ≥75) must be installed in the oil inlet line.

Electrical connection

Connect the DC24V power supply correctly and pay attention to the polarity.

Connect the control signal line to the corresponding pins of the amplifier (such as ±10V and the common terminal).

Ensure that the cable shielding layer is reliably grounded.

Oil drain port: If the valve has an independent oil drain port (Y port), it must be directly connected back to the oil tank without back pressure.

Basic operation process:

System flushing: Before installing the valve, the hydraulic system must be thoroughly flushed until the cleanliness meets the standard.

Electrical inspection: Confirm that the power supply voltage and signal voltage are correct.

Zero-point calibration: For high-precision applications, it may be necessary to give the amplifier a “zero-point calibration” signal when the system starts up.

Parameter Settings: Set the control parameters and ramp time in the controller that match the valve’s flow gain and the A1V-655 parameter set.

Trial operation: Start from a small signal and test slowly to observe whether the actuator moves smoothly and symmetrically without any crawling phenomenon.

Monitoring and maintenance: Regularly check the system oil temperature and filter pressure difference, and conduct regular oil analysis.

6.4WREE6 series product list
The 4WREE6 series is mainly distinguished by the type of valve core, rated flow, electrical options and control parameters. The following are some typical model examples:

4WREE 6 E1X-20/G24K31/A1V

E1X: Different valve core functions, such as negative covering, are used for applications that require smoother start-up.

20: Smaller rated flow rate, such as 20 L/min.

4WREE 6 E16-40/G24K31/A1V

E16: Positive cover valve core, used for applications that require shock resistance and low leakage.

40: Larger rated flow rate, such as 40 L/min.

4WREE 6 E08-22/G12K0/A1V

G12: The power supply voltage is DC12V.

4WREE 6 E08-22/G24K31/*A5V-820***

*A5V-820* : Different sets of control parameters, featuring faster dynamic response or different flutter frequencies.

4WREE 6 E08-22/B24K0/A1V

B24: It represents a basic type amplifier, and its functions may be simplified compared to the standard type (G).
This series of products mainly forms detailed models through differences in specifications, control methods, interface parameters, etc. The common complete models are as follows: