3582 Series Pneumatic and Type 3582i Electro-Pneumatic Valve Positioners
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Type 3582NS positioners meet typical requirements of the nuclear power industry. The Type 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/Nomex. EPDM demonstrates superior temperature capability and shelf life over nitrile. (Use a clean, dry, oil-free air supply with instruments containing EPDM components. EPDM is subject to degradation when exposed to petroleum-based lubricants.) The Nomex diaphragm fabric demonstrates improved strength retention at elevated temperature and radiation conditions.
In addition, the Type 3582NS positioner is qualified “commercial grade dedicated” under Fisher’s 10CFR50, Appendix B, quality assurance program. These can be supplied as 10CFR21 items.
The Type 3582i electro-pneumatic valve positioner consists of a Type 582i electro-pneumatic converter installed on a Type 3582 pneumatic valve positioner. The Type 3582i provides an accurate valve stem position that is proportional to a dc current input signal.
The Type 582i electro-pneumatic converter, shown in figure 5, is a modular unit that can be installed at the factory or in the field. (Upgrading an existing 3582 Series unit by field installation of a Type 582i electro-pneumatic converter may require changing the existing positioner mounting and the input signal range. Please contact your Fisher sales office when planning an upgrade). 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.