Can two control valves be used with one pressure transmitter? For example
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Can two control valves be used with one pressure transmitter? For example, thank you!
Of course, step control can be used: when the PID output is between 0 and 50, one valve corresponds to an output of 0 to 100; when the PID output is between 50 and 100, another valve corresponds to an output of 0 to 100
It’s possible; as mentioned above, it can be used for step control!
Well, what’s wrong with that? The process requirements can be extremely varied, and for a given pressure, there may be multiple factors that need to be adjusted.
Step control is one method; adjusting the large and small valves is also a method (one for coarse adjustment, one for fine adjustment)
We’ve used one without any stage control either; both valves operate simultaneously, with one discharging directly and the other feeding into another tank. It was strange at the time too, but it worked.
For example, this is exactly what happens with the double-acting slide valve used for flue gas pressure or pressure difference control in catalytic reactions.
The poster’s question needs to be corrected; valves cannot control transmitters – it is flow, pressure, temperature, etc. that are the controlled variables, with valves serving as actuators.