Fisher 3720 electro-pneumatic positioners are designed for use with either diaphragm or piston rotary actuators.
These positioners provide a valve ball or disk position for a specific input signal. The 3720 is created by the addition of a Fisher 3722 electro-pneumatic converter to the 3710 positioner. The positioner provides a valve position in response to a DC current input signal and can easily be configured as single- or double-acting for rotary actuators.