Fisher 3722 Electro-Pneumatic Converter

Technical Specifications

Model：3722 Brand：Fisher Product Type: Electro-pneumatic I/P converter module for 3700 series positioner

Module Feature

Fisher 3722 is compact modular electro-pneumatic converter. It receives 4-20mA DC analog control signal and converts electric current into proportional pneumatic pressure signal. It can be mounted directly onto Fisher 3710 pneumatic positioner to build 3720 electro-pneumatic positioner. Rugged aluminum housing, stable output under vibration and temperature variation. Widely used for rotary ball/butterfly valve control in oil, gas, chemical and power plant.

Working principle: Convert 4-20mA DC current signal into proportional pneumatic pressure signal for positioner input Onboard components: Electromagnetic coil, nozzle flapper unit, amplifier relay, terminal block, aluminum housing, mounting gasket

LED indicators

Not equipped

Hardware self-diagnosis

Visual inspection, coil continuity test, signal conversion test, zero/span calibration, air tightness test

Programming software

No dedicated software required

Electrical & Pneumatic Parameters

Input signal:4-20mA DC Supply air:20~150psi clean dry instrument air Pneumatic output:3-15psi

Mechanical & Structure

Mounting: Direct bolt-on installation on base of 3710 positioner Protection class:IP66

Environmental

Operating temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non-condensing Certification:ATEX,CE,IECEx Status:Fisher 3700 series I/P converter module

System compatibility

Designed exclusively for Fisher 3710 rotary pneumatic positioner, matched with rotary piston or diaphragm actuators, ball valve and butterfly valve.

Function

3722 is electro-pneumatic converter manufactured by Fisher. It transforms 4-20mA control signal from DCS system into pneumatic signal to feed into 3710 positioner. This modular design allows field upgrade from pure pneumatic positioner to electro-pneumatic type without replacing the whole positioner assembly. Coil damage or nozzle blockage causes signal conversion failure and valve positioning error.

Installation

Follow lockout/tagout safety procedure before installation. Cut off instrument air and power supply. Mount 3722 converter onto 3710 positioner base and install sealing gasket. Wire 4-20mA signal cable, connect instrument air tubing. Perform zero/span calibration and full valve stroke test.

Interface

Electrical terminal block for 4-20mA input, pneumatic supply port and pneumatic signal output port to 3710, bolt mounted on positioner base, no LED indicators on 3722.

Diagnostic

No pneumatic output: Coil open circuit or loss of supply air. Output pressure drift: Dirty nozzle or incorrect zero/span. Unstable pneumatic signal: Gasket leakage inside converter.

Product Brief

3722 Fisher electro-pneumatic I/P converter module,converts 4-20mA DC signal to 3-15psi pneumatic signal,used to upgrade 3710 pneumatic positioner to 3720 electro-pneumatic positioner for rotary control valve.