Pneumatic butterfly valve is usually composed of pneumatic actuator, valve body and some accessories connected, installed and debugged. This article mainly introduces the precautions for the field use of pneumatic butterfly valves.
According to the on-site personnel who reported that the equipment could not operate normally, the company sent technicians to the site to understand the situation. The following are some problems and solutions.
1. The signal valve sent by the control cabinet does not act. According to the 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 cannot work normally.
Solution: Remove the solenoid valve to remove the strong current interference from 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 a 4 to 20 mA signal, so it is not necessary to install the solenoid valve when the positioner is installed).
2. After the automatic switch to the manual state, the switch cannot return to the automatic state; Because the field operator used too much force to pull the clutch too much, the internal gear was stuck and the automatic gear could not be pulled back.
Solution: When pulling the clutch, the hand wheel should be rotated back and forth to disengage the internal turbine, so as to easily achieve manual and automatic switching (when manual and automatic switching, you must pull up the yellow ferrule next to it).
3. The valve works normally, but the feedback is always 100%. The field wiring personnel know that the field wiring is thick, and the strong hardness connection is not very convenient, resulting in a screw falling off. The wiring personnel directly take a long screw to tighten it, so that the module is pushed to the top by the screw, causing a short circuit.
Solution: Replace the conventional screw model; It is recommended to use thin wires for connecting lines.
