Common faults and treatment methods of electric valves

1. The indication of the electric valve in the OM screen is incorrect
  Cause analysis: through this phenomenon can be judged the sealing of the electric valve, as well as the valve body, the mechanical part of the motor head operability are maintained well, such problems are compared with manufacturers, the defect is that the action point of the electric head limit switch is inconsistent with the actual position of the valve body, and the limit switch needs to be readjusted by the mechanic.
 Solution: Open the box and manually adjust the electric valve to the fully closed position, if it is an electric valve controlled by 02, it is necessary to switch the starting structure to check the torque switch and press down.
2. When the valve is opened, it cannot reach the specified position
   Reason analysis: the valve electric manual can not make the valve open to the full open position, and the opening torque is large, and the fault judgment is that the valve stem thread is partially damaged; uneven pitch; There is a foreign object stuck inside the valve.
 Treatment: If the stem or stem nut is damaged, it should be crowned in time; If there is a foreign body jam, it is necessary to disassemble the valve to clear the foreign body and solve it from the source.
3. The local valve is not transmitted, and the motor heats up too fast
 Cause analysis: Because the power supply of the motor is out of phase, the switch should be pulled down immediately after this phenomenon occurs to avoid burning the motor. The cause of phase loss is terminal virtual connection, cable breakage, and poor contact of a certain contact of air switches, contactors, and thermal relays.
 Solution: Tighten each terminal block. In the event of a power failure, the resistance of each contact is measured with a multimeter, and the faulty point is identified according to the size of the tissue and replaced.