Can a pneumatic control valve work without positioner?
Answer Posted / carl_ellis
Yes, a pneumatic actuator can drive a valve without a
positioner.
In the HVAC world it's done all the time because the service
conditions (temperature/pressure/wear factor) for, say, a
chilled water valve does not necessarily demand the
precision control that a positioner offers.
An I/P (a current to pneumatic transducer) is used to
convert a 4-20mA control signal to a pressure control signal.
The service required in heavy process industries is usually
sever enough that a positioner is used on a control valve.
Company and industry practice will determine the use of a
positioner.
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