Regarding the frequent operation of control valves
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In automatic mode, control valves are generally sensitive to frequent opening and closing. In such cases, it is necessary either to stabilize the operating conditions or to reset the PID parameters. However, in PSA pressure swing adsorption units, the control valves operate very frequently. It has hardly ever been stable. So what is the difference between the control valves in PSA units and those in ordinary devices? Why can the control valves in PSA units operate frequently?
Differences between control valves in PSA units and those in ordinary units: on-off shut-off valves
Hello LZ: 1. The control valves in PSA are the same as those in other systems, as control valves are generally classified based on their internal structure, such as single-seat valves, sleeve valves, diaphragm control valves, etc. As a manufacturer of control valves, they generally select the appropriate model based on your operational parameters, choosing the right valve for different pressure differences, flow rates, temperatures, and properties of the medium ； 2. Control valves are generally not intended to operate frequently, as such frequent operation can cause disturbances in the operating conditions, and it also affects the service life of the valve and its accessories ； 3. There are many possible reasons for frequent valve operation, listed as follows: a. Improper selection of the valve’s Cv value and flow characteristics, resulting in frequent valve operation ； b. The sensitivity of the parameter being adjusted is too high; for example, when adjusting the water temperature with a target value of 25 degrees and a tolerance of plus or minus 1 degree, the narrow range of adjustment can lead to frequent valve operations ； c. Air leakage at the actuator of the valve, the connections to the accessory air pipes, etc., causes the locator to require frequent air replenishment, leading to repeated operations ； d. Improper valve installation location, resulting in highly chaotic flow of the medium and triggering oscillations ； The above is just something written based on my own understanding; if there are any mistakes, please feel free to point them out.