Several parts that must be overhauled during the overhaul of pneumatic actuators
Pneumatic actuator maintenance can be divided into minor repairs and overhauls. The main content of minor repairs is based on the causes of valve failures and targeted maintenance measures are taken. The content of overhauls must be overhauled during the overhaul of the following components.
1. Overhaul of spool valve
The long-stroke actuator of the spool valve is the command mechanism that guarantees the up and down movement, so during the maintenance, it should be ensured that the action is flexible and the position is correct. When in the middle, the upper and lower cylinder pressures should be balanced accordingly. During maintenance, check the damage to the sealing surface of the valve body, repair or replace the severely damaged parts. After the spool valve is disassembled and overhauled, clean it with washing oil to remove the dirt on the valve seat and valve sleeve, and then add a small amount of vacuum grease.
2. Overhaul of the cylinder
The cylinder must not be disassembled frequently. When replacing the "O"-shaped rubber sealing ring, remove the air supply connector, disconnect the connection between the cylinder output lever and the rocker arm, then loosen the fixing screw, open the upper cover to pull out the valve cover, and replace the "O"-shaped rubber Seal ring. Then carry out a leak test, add the rated pressure and the pressure drop after 5min shall not be greater than 5kPa.
3. Overhaul of balance valve
When the manual-automatic switch fails, it should be disassembled for maintenance, and vacuum grease should be applied after maintenance.
4. Positioner calibration
Confirm that the positioner is properly connected to the valve, and the installation is tight. Check and confirm the connection of the electric circuit and the air circuit, open the manual isolation valve of the air source, and adjust the pressure adjusting bolt of the pressure reducer to make the air supply pressure of the positioner within the specified range.
