WOODWARD 8901-457 Current-Pressure (I/P) Converter

the Woodward 8901-457 is a high-precision Current-to-Pressure (I/P) Transducer, specifically designed for industrial turbine and engine control applications.

It acts as the critical interface between electronic control systems and pneumatic actuators, converting a standard electrical signal into a proportional pneumatic output to position valves or fuel racks.

Technical Parameter Table

Related Models

The 8901-457 is often utilized alongside these Woodward components:

8200-1300: 505 Series Digital Governor (provides the 4-20mA control signal).1

9907-162: 505 Turbine Controller.2

ProTech-GII: Overspeed protection systems that may trigger the I/P transducer for emergency shutdown.3

CPC II: Current-to-Pressure Converter (a more modern, high-precision electronic alternative).

Application Cases

Steam Turbine Control: Regulating the position of the steam governor valve to maintain constant speed or load.

Gas Turbine Fuel Systems: Controlling the fuel metering valves through pneumatic actuation.

Process Industry Valves: Used in refineries and chemical plants to control large-scale pneumatic control valves where electrical-only actuators are impractical.

Boiler Feedwater Systems: Managing the modulation of feedwater valves based on boiler demand.

Product Advantages and Features

Explosion-Proof Design: Certified for use in hazardous areas (Class I, Div 1), making it ideal for oil and gas environments.

Vibration Resistance: Specifically engineered to be mounted directly on or near high-vibration equipment like turbines and engines.

High Flow Capacity: Delivers high pneumatic flow rates, allowing for faster response times in large actuators.

Low Air Consumption: Optimized internal pilot valves minimize the amount of compressed air wasted during steady-state operation.

Field Adjustable: Includes zero and span adjustments that are easily accessible for calibration during commissioning.

Other Models in the Same Series

The Woodward 8900/8901 family includes various pressure and signal configurations:

8901-456: Variant with 6–30 psi output range.

8901-458: High-pressure output variant for heavy-duty actuators.

8901-460: Model with internal pressure feedback for enhanced stability.

8910 Series: Low-cost variants for non-hazardous locations.

Introduction

The Woodward 8901-457 is a rugged, field-proven I/P transducer that bridges the gap between digital control logic and mechanical execution.

By translating a 4-20 mA current signal into a highly accurate 3-15 psi pneumatic signal, it allows sophisticated electronic governors to control heavy pneumatic machinery with extreme precision.

Its NEMA 4X housing and vibration-dampened internals ensure a long service life even when exposed to the corrosive and turbulent atmospheres of power plants and refineries.