Pneumatic butterfly valve is usually composed of pneumatic actuator, valve body and some accessories. This paper mainly introduces the matters needing attention in the field use of pneumatic butterfly valve.
According to the site personnel reflect that the equipment can not operate normally, the company sent technical personnel to the site to understand the situation, the following are some problems and solutions.
1. The control cabinet sends signal and the valve does not act. After field observation, the pneumatic regulating butterfly valve is installed with a solenoid valve on the premise of installing the positioner. The strong current of the solenoid valve interferes with the signal output of the control cabinet, and the valve cannot receive the signal, so it can not work normally.
Solution: remove the solenoid valve, remove the strong current interference, the normal operation of the equipment (Note: the function of the solenoid valve is to switch the valve, and the function of the positioner is to control the opening of the valve with 4 to 20 mA signal, so it is not necessary to install the electromagnetic valve under the premise of installing the positioner).
2. After the automatic switch to manual mode, the automatic mode cannot be switched back to automatic mode; due to the excessive force applied by the field operator, the clutch pulling amplitude is too large, resulting in the internal gear stuck and unable to pull back the automatic.
Solution: when pulling the clutch, the hand wheel should rotate back and forth to release the internal turbine, so as to easily achieve manual automatic switching (when the manual automatic switching, the yellow color card sleeve must be pulled up).
3. The valve works normally, but the feedback has been in 100% state. The field wiring personnel only knew that the on-site wires were thick wires with strong hardness. The connection was not very convenient, resulting in a screw falling off. The wiring personnel directly tightened a long screw, so that the module was pushed by the screw, causing a short circuit.
Solution: replace the conventional screw model; it is recommended to use thin wire instead of connecting line.