Investigation into the reason why the on-site valves of DCS did not operate
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The DCS sends a digital command; the DCS does generate a switch signal, but the field actuator does not respond. What could be the reason?
Issues with the on-site signals, or problems with the on-site actuators.
The simplest reason is insufficient air supply pressure
1. Check whether the air supply for the valves on site is functioning properly (for pneumatic valves); electric valves are a different matter； 2. Check the signal of the on-site valve positioner/solenoid valve, depending on whether the on-site valve is a on/off valve or a control valve ； 3. In the case where the 2 signal is not received, check whether there is a signal in the on-site junction box ； 4. The valve is stuck inside; this depends on the specific conditions on site, such as whether there is scaling in the medium. That’s all for now; those points that haven’t been covered fully should be added by those who follow. . Haha
The most reliable method is to use a multimeter to make the measurement directly on the switch valve
Following normal logic, the first step is to go to the site and check if there is a signal; if there is a signal and the air supply is working properly, then check the valves
1. Check whether the signal is being sent to solenoid valves, positioners, electric actuators, etc. 2. For pneumatic valves, check if there is sufficient air supply; for electric valves, check the power supply. 3. If both of the above are normal, then check whether the solenoid valves, positioners, and electric actuators are damaged. 4. Check if the valve is stuck