Pneumatic butterfly valves are usually composed of a combination of pneumatic actuators, valve bodies, and accessories that are connected, installed, and debugged. This article mainly introduces the precautions for on-site use of pneumatic butterfly valves.

In mid June 2013, a blower factory in Shandong purchased a batch of pneumatic regulating butterfly valves for use in sewage treatment in the Xinjiang West East Gas Pipeline Project. According to on-site personnel, the equipment could not operate normally. The company sent technical personnel to the site to understand the situation. The following are some of the problems and solutions.

1. The control cabinet sent a signal that the valve did not act. After on-site observation, the pneumatic regulating butterfly valve was installed with a locator and an electromagnetic valve was added. The strong electrical interference of the electromagnetic valve affected the signal output of the control cabinet, and the valve could not receive the signal, so it could not work normally.

Solution: Remove the solenoid valve and remove strong electrical 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 locator is to control the valve opening with a 4 to 20 milliampere signal, so it is not necessary to install an solenoid valve with a locator installed).

2. After automatically switching to manual mode, it does not switch back to automatic mode; Due to the use of excessive force by the on-site operator, the clutch was pulled too far, causing the internal gears to jam and unable to retract automatically.

Solution: When pulling the clutch, the handwheel should rotate back and forth to disengage the internal turbine, making it easy to achieve manual automatic switching (be sure to pull up the yellow sleeve next to it).

3. The valve is working normally, but the feedback has been in a 100% state. It was only through the on-site wiring personnel that they found out that the wires on site are all thick wires with strong hardness, which makes it inconvenient to connect, resulting in a screw falling off. The wiring personnel directly tightened a long screw, causing the module to be pushed against by the screw and causing a short circuit.

Solution: Replace with a regular screw model; Suggest using thin wires for the connected lines.