Views: 198 Author: Site Editor Publish Time: 2021-02-21 Origin: Site
In mechanical operation, compact pneumatic actuator plays a vital role. This requires everyone to understand the installation, debugging, maintenance and failure analysis of pneumatic actuators. Only correct installation and operation and necessary maintenance can make the maintenance work of pneumatic actuated valves achieve the desired effect and application purpose.
1. Installation of actuator and valve
After getting the single acting pneumatic cylinder or double acting pneumatic cylinder, first check whether the cylinder model is correct, and check whether the cylinder is open or closed. Normally, it is closed during installation.
Check the rotation direction of the cylinder, turn the valve counterclockwise to open the valve, and turn clockwise to close the valve.
When connecting the cylinder and the valve, check whether the center distance of the connecting hole of the cylinder is consistent with the center distance of the connecting hole of the valve flange.
Check whether the axis of the cylinder is consistent with the axis of the valve. If the axis is inconsistent, install a square sleeve.
The cylinder must be in the same state as the valve during installation.
The butterfly gate valve and the actuator are installed at 90 degrees (no special requirements). The actuated ball valve and the actuator are installed in parallel.
2. Install solenoid valve (as required)
After installing the air powered actuator, install motorized solenoid valve if necessary. You should pay attention to whether the O-ring on the solenoid valve is intact. After installation, ventilate to see if the valve is fully closed, otherwise remove the solenoid valve and reinstall it by 180 degrees.
3. Install the reply device
First, remove the screws on the indicator cover at the upper end of the cylinder, insert the connecting shaft of the echoer into the groove of the central shaft of the cylinder, and then fix the connecting bolts.
Open the upper cover of the responder and check whether the stroke stop corresponds to the valve switch.
4. Debugging
In the absence of air actuated solenoid valve, ventilate from one end first to see if the valve is in place or not. Under normal circumstances, the left side of the actuator is for open valve, and the right side is for closed valve.
After installing the solenoid valve, ventilate first to see if the valve is fully closed, otherwise check the solenoid valve and valve installation status.
1. The control valve does not operate, such as no signal or air source, air source and no signal, positioner without air source, positioner with air source but no output, and signal without action. The solution includes replacing the solenoid valve, replacing the coil, and cleaning the dirt.
2. The movement of the control valve is unstable.
3. The control valve vibrates.
4. The action of the regulating valve is slow.
5. The leakage of the regulating valve increases.
5. The adjustable range of flow becomes smaller.
The purpose of use and maintenance of pneumatic actuator control system is to extend valve life and ensure reliable opening and closing.
The thread of the valve stem often rubs against the nut of the valve stem. Apply a little yellow dry oil, molybdenum disulfide or graphite powder for lubrication.
For valves that are not frequently opened and closed, turn the handwheel regularly to add lubricant to the valve stem threads to prevent seizure.
Always check and maintain the integrity of other parts of the valve. If the fixing nut of the handwheel falls off, it must be equipped and cannot be used properly, otherwise it will round off the upper four sides of the valve stem, gradually losing the reliability of the fit, and even unable to start.
