How to use 4WEH16 electro-hydraulic reversing valve

4WEH16 electro-hydraulic reversing valve is a medium and high-pressure reversing valve that combines electromagnetic control and hydraulic drive. It is widely used in construction machinery, metallurgical equipment, plastic machinery and other scenarios where hydraulic oil flow direction and pressure are required to accurately control. Its core function is to control the valve core position through the on-off power of the solenoid to realize the start, stop, reversal and flow adjustment of the hydraulic system. The following are the detailed usage methods and precautions:

1. Structure and working principle

Basic structure valve body: It adopts high-strength cast iron or steel structure, and withstands high pressure (usually 31.5MPa/40MPa optional).

Valve spool: conical valve or slide valve design, position switching is achieved through solenoid drive.

Electromagnet: Wet electromagnet (protection level IP65), optionally available for AC (AC) or DC (DC).

Pilot control: Some models of integrated pilot valves control the operation of the main valve core through small flow rate to reduce the power demand of the solenoid.

Manual emergency device: equipped with a manual reversing rod to manually operate the valve core position in the event of power failure or failure.

Working principle: The solenoid is energized and a magnetic field is generated to push the valve core to move, changing the direction of hydraulic oil (such as P→A, B→T).

Power off state: Spring reset brings the valve core back to the middle, hydraulic oil passage is closed or oil return (depending on the median function).

Pilot control: The pilot valve acts first, pushing the main valve core by controlling pressure oil to achieve remote or low-pressure control.

2. Prepare before use

Check the cleanliness of the installation environment: Make sure that the installation surface is free of impurities and avoid leakage caused by scratches on the valve body seal ring.

Temperature range: working temperature -20℃~+80℃ (Special models can be expanded to -40℃~+120℃).

Vibration and impact: Avoid installation near the vibration source to prevent the valve core from being stuck or the electromagnet loose.

Hydraulic system matching pressure matching: The maximum system pressure must not exceed the rated pressure of the valve body (such as rated pressure of 4WEH16E7X/6EG24NZ5L 31.5MPa).

Flow matching: Select the system flow according to the valve port diameter (such as 16mm) to avoid exceeding the maximum flow (such as 160L/min) and causing valve core wear.

Oil cleanliness: The filtration accuracy must reach NAS level 9 or ISO 18/15 to prevent impurities from jamming the valve core.

Electrical connection voltage matching: Make sure that the solenoid voltage (such as 24V DC or 220V AC) is consistent with the power supply to avoid burning the coil.

Wiring method: Shielded cables are used to reduce electromagnetic interference, and the fastening torque of the terminals meets the requirements of the instructions (such as 0.6-0.8N·m).

Grounding protection: The solenoid shell needs to be reliably grounded to prevent leakage from injuring people.

3. Operation steps

Manual initial commissioning median confirmation: When power is not turned on, manually operate the emergency rod to put the valve core in the middle and check whether the hydraulic cylinder is stationary.

Commutation test: Slowly energize an electromagnet (such as 1YA) to observe whether the hydraulic cylinder extends smoothly without crawling or impact.

Reverse test: After power is cut off, switch to another electromagnet (such as 2YA), the hydraulic cylinder should move in reverse, and there is no high back pressure in the return oil circuit.

Electrical control integrated PLC programming: Set the electromagnetic on-off logic in the PLC (such as P→A when 1YA=1, and P→B when 2YA=1).

Delay control: For large inertial loads, 0.1-0.5 seconds delay can be added to the commutation signal to avoid hydraulic shock.

Interlock protection: 1YA and 2YA interlock are realized through hardware or software to prevent the valve core from being stuck due to power on at the same time.

Parameter optimization response time adjustment: shortens the commutation time (typically 20-50ms) by adjusting the pilot valve pressure or solenoid current.

Flow adjustment: Some models are equipped with flow adjustment screws, which can fine-tune the valve opening to control the speed of the hydraulic cylinder.

Median function selection: Select O-type (closed), H-type (return oil) or Y-type (decompression) median function according to needs.

4. Maintenance and troubleshooting

Daily maintenance

Sealing inspection: Check the O-ring and combined gasket every 500 hours, and replace it in time if it is found to have aging or leaks.

Oil replacement: Replace hydraulic oil regularly according to the equipment requirements (such as every 2000 hours), and clean the oil tank and filter element at the same time.

Electromagnet cleaning: Use dry compressed air to purge the surface of the solenoid to prevent degradation of insulation performance.

Common faults and handling

Solutions to possible causes of failure phenomena

The valve core does not move the solenoid burns, the coil is broken, the valve core is stuck and replaces the solenoid, cleaning the valve core, checking the electrical connection

The pilot pressure of the reversing impact is too high, the valve core return spring is fatigued to adjust the pilot valve pressure, and the spring is replaced

Severe leakage of seal ring damage, valve body cracks, loose connections to replace seals, welded valve body, fastening bolts

Responsive to slow oil viscosity too high and the electromagnet is insufficient to replace the low viscosity oil, check the power supply voltage

Long-term disabling treatment

Anti-rust treatment: Apply anti-rust oil on the surface of the valve core, and seal the solenoid port with a plastic plug.

Storage environment: Place it in a dry and ventilated place to avoid direct sunlight and corrosive gases.

Regular power-on: Power on every 3 months (10 minutes each time) to prevent the solenoid coil from getting damp.

5. Safety precautions

High pressure hazard: Make sure the system pressure has been released before operation, and the valve body is not removed with pressure.

Electrical safety: After power outage, you need to use a multimeter to confirm that there is no voltage before electrical maintenance can be carried out.

Thermal protection: When working for a long time with large flow, the surface temperature of the valve body may exceed 70℃, and a heat insulation board or warning sign must be installed.

Spare parts management: Store commonly used consumable parts (such as sealing rings, electromagnets) to avoid failure and downtime.