FO valve forward and reverse action
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There is an FO control valve: the control room sets it at 25% while the field value is 75%. What could be the reason for this? How can it be configured so that the values in the control room and the field are identical? What is the function of a locator? I study engineering, so I don’t really understand the mechanics of instruments
In FO mode, with air-shut operation, the valve is fully open at 4 mA (the current setpoint of 0%) and fully closed at 20 mA (the current setpoint of 100%). It is necessary for the DCS configuration personnel to change the AO output setting from air-open to air-shut, so that 20 mA is output when the setpoint is 0% and 4 mA is output when the setpoint is 100%
The range of the AO output module can be changed; it was originally 4-20mA, and changing it to 20-4mA will do
Please tell me which brand of DCS or PLC it is, and Haiyou can provide more specific assistance to you.
Just change the reaction on the locator directly, that’s it