The DCS sends a signal to open the valve fully, but it only opens halfway on site – what’s the problem?
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Is it a problem with the locator, or something else? What are the possible faults?
One option is to re-tune the locator; nowadays, locators usually come with an automatic tuning function. Another thing is that if it’s the wind valve that’s opening, check whether the wind pressure is sufficient or if there’s a blockage in the air path.
In short, first measure whether the output current of the card is 12, 20, or 4. If it is 12, then look for the cause within the system; issues such as range setting or limit settings could be the problem.
Listen to me first; check the current signal first. If the output value matches the desired opening degree of the valve, then investigate the reasons on-site
System reasons? Is it maybe the program that’s wrong?
Regarding hardware, are there any other potential issues? It would be best to list them
First, clarify what kind of valve it is and what signal the DCS provides Is it AO or DO?
1. Measure on-site to check whether the signal is consistent with the DCS full-open signal； 2. If the signals are consistent, check whether the transmitter and actuator are stuck ； 3. Check whether the gas and electrical circuits are in good condition ； Thank you. I’m not sure if it can meet your requirements ；
1. First, measure the current output to the locator to see if it matches the signal provided by the DCS 2 Check whether the output pressure of the positioner meets the working pressure requirements of the cylinder 3 Check if the cylinder is leaking air Has the connecting part fallen off? 4 If everything else is fine, then it’s possible that the valve core is stuck.
1. Check the valve setting: determine what opening degree corresponds to 4-20 (assuming the DCS output is 4-20 MA) milliamps. 2. Adjust the valve for self-tuning. 3. Check if the pressure is sufficient; try increasing it