Maintenance method of 4WEH16 electro-hydraulic reversing valve

The maintenance methods of 4WEH16 electro-hydraulic directional valve are as follows:

General appearance and connection inspection:

Check the valve body, valve cover, and flange connections: Check for signs of leakage, such as oil stains, water stains, rust spots, etc. If leakage is found, the connecting parts need to be tightened or the seals replaced in time.

Observe the anti-corrosion layer on the surface of the valve: Check whether the anti-corrosion layer has fallen off. If it does, it should be repainted in time to prevent rust and corrosion of the valve body.

Remove oil and dust from the valve surface: especially clean the valve stem and sealing parts to prevent impurities from invading the sealing surface and affecting the sealing performance. Can be wiped with a clean soft cloth or special detergent.

Valve stem and transmission mechanism maintenance:

Add designated grease: According to equipment requirements, add designated grease, such as lithium-based grease, high-temperature grease, etc., to the valve stem and transmission mechanism to avoid dry friction, reduce wear and extend service life.

Regular manual opening and closing: For normally open or normally closed 4WEH16 electro-hydraulic directional valves, manually open and close 1-2 times regularly to prevent the valve stem from getting stuck, especially for valves working in high temperature and corrosive environments.

Thread pair and gearbox maintenance:

Clean the old grease: Clean the old grease in the thread pair and gear box to ensure the interior is clean.

Apply new grease: Apply new valve-specific grease to ensure good lubrication of the thread pair and gearbox, reducing wear and failure.

Low pressure seal test:

Close the valve: Close the valve and make sure the valve is fully closed.

Pressure test: pressurize the outlet end of the valve, for example to 0.6MPa, and observe whether the pressure drops. If the pressure drops, it means that the valve has a leakage problem and needs further inspection and treatment.

Stuffing box maintenance:

Leakage treatment: If leakage occurs at the valve stem, press the packing gland bolts evenly, but do not over-tighten to avoid blocking the valve stem. If it still leaks after tightening, consider replacing the packing, such as graphite packing.

Handwheel/handle inspection:

Check the fixing bolts: Check whether the fixing bolts of the handwheel and handle are loose. If they are loose, tighten them in time to ensure that the handwheel and handle can operate flexibly.

Electric/pneumatic actuator inspection:

Check the power supply and gas supply pipelines: Ensure that the power supply and gas supply pipelines are connected properly and have no damage, leakage or other problems.

Clean the filter: Clean the filter regularly to prevent impurities from clogging the filter and affecting the normal operation of the actuator.

Test stroke positioning: Test whether the stroke positioning of the electric/pneumatic actuator is accurate to ensure that the valve can accurately open and close to the specified position.

Internal cleaning and sealing surface inspection:

Disassemble the valve: If necessary, disassemble the valve and remove scale, welding slag and other impurities on the valve cavity, sealing surface and valve seat. You can use a soft brush and special cleaning agent to clean, and pay attention to protecting the sealing surface to avoid scratches.

Check the sealing surface wear/corrosion: Check the valve seat and valve disc sealing surface wear and corrosion. If minor damage occurs, grinding and repair can be performed; if the damage is severe, the sealing surface or related components need to be replaced.

Replace aging parts:

Replace aging packing, O-rings, gaskets: Regularly check and replace aging packing, O-rings, gaskets and other sealing components to ensure the sealing performance of the valve. When replacing, choose parts with compatible materials, such as PTFE, metal wound pads, etc.

Assembly and testing:

Assemble according to the order of the manual: Assemble the valve according to the order of the equipment manual, tighten the bolts evenly, and use diagonal tightening to ensure that the valve is firmly assembled.

Test the opening and closing torque: When operating the valve with the handwheel, ensure smooth operation without obstruction; for electric actuators, the limit switch needs to be adjusted to ensure that the valve opens and closes normally.