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Difference between revisions of "Positioners"
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[[File:Positioners.jpg|thumb|right|Positioners]] | |||
'''Positioners''' are used to control the opening or closing of the actuator based on electric, or pneumatic signals.A positioner positions a valve by comparing the input signal with a mechanical feedback link from the actuator. It then produces the needed force to move the actuator output until the mechanical output position feedback corresponds with the pneumatic signal value. Positioners can also modify the valve's action , alter the stroke or controller input signal , increase the pressure to the valve actuator or alter the control valve flow characteristic . | |||
==Features== | |||
* Positioners use feedback information to ensure that [[Actuators]] are in the correct position. | |||
* Can assist in overcoming friction and greater actuating pressures are available. | |||
* Works on principle of Pressure Balance. | |||
* Rugged construction. | |||
* Amplify pressure to the actuator. | |||
* Allows characterisation either mechanically or electronically . | |||
* Negates variable process reaction pressure effect on position. | |||
* Allows split ranging. | |||