Fisher 3582 pneumatic valve positioners and 3582i
electro-pneumatic valve positioners,are used with diaphragm-actuated, sliding-stem control valve assemblies. The pneumatic valve positioners receive a pneumatic input signal from a control device and modulate the supply pressure to
the control valve actuator, providing an accurate valve stem position that is proportional to the pneumatic input signal.
3582NS positioners are designed for nuclear power
applications. The 3582NS construction includes
materials that provide superior performance at
elevated temperature and radiation levels. The O-rings
are EPDM (ethylene propylene) and the diaphragms
are EPDM/meta-aramid. EPDM demonstrates superior
temperature capability and shelf life over nitrile.
The meta-aramid diaphragm fabric demonstrates
improved strength retention at elevated temperature
and radiation conditions.
The 3582i electro-pneumatic valve positioner consists
of a Fisher 582i electro-pneumatic converter installed
on a 3582 pneumatic valve positioner. The 3582i
provides an accurate valve stem position that is
proportional to a DC current input signal.
The 582i electro-pneumatic converter is a modular unit that can be installed at the factory
or in the field.
The converter receives a DC current input signal and
provides a proportional pneumatic output signal
through a nozzle/flapper arrangement. The pneumatic
output signal provides the input signal to the
pneumatic positioner, eliminating the need for a
remote mounted transducer.