Woodward 9907-1199 Advanced CPC-II Current-to-Pressure Converter

Woodward 9907-1199: Advanced CPC-II Current-to-Pressure Converter

The Woodward 9907-1199 is a second-generation Current-to-Pressure Converter (CPC-II) designed to provide ultra-precise hydraulic pressure control for steam turbine valve actuators.

Built specifically for hazardous environments (Zone 1 and Zone 2), it translates a standard 4–20 mA electrical demand signal into a proportional hydraulic output.

Its primary role is to interface electronic governors with hydraulic mechanical systems, ensuring the turbine’s speed and load are managed with industrial-grade stability.

Technical Parameter Table

Product Advantages and Features

“Silt Buster” Technology: A patented self-cleaning routine that periodically clears internal silt and debris, drastically reducing downtime caused by contaminated oil.

Redundancy Ready: Can be configured to accept dual 4–20 mA inputs (Master/Slave) for mission-critical applications where signal loss is not an option.

High Contamination Tolerance: Designed to “power through” particles up to 40 $\mu$m, making it significantly more robust than traditional I/H converters.

Fail-Safe Operation: Features an internal return spring that forces the control port to drain upon loss of power or internal failure, safely closing turbine valves.

Linearization Table: Includes an 11-point digital linearization table to compensate for non-linear valve characteristics.

Unique Product Description

The Woodward 9907-1199 is famously known as the “Filter Killer.” In the world of steam turbines, oil contamination is the leading cause of governor failure.

The 9907-1199 tackles this head-on with an actuator four times stronger than its predecessors and its unique Silt Buster algorithm.

It is essentially a high-tech “translator” that doesn’t just pass signals—it cleans itself while doing so, ensuring that the heavy hydraulic “muscles” of a turbine follow the electronic “brain” without hesitation or drift.

Application Cases

Steam Turbine Control: Precisely positioning single-acting governor valves in power plants and refineries.

Hazardous Oil & Gas Zones: Operating safely in environments where explosive gases may be present (Zone 1/Div 1).

Retrofit Projects: Replacing legacy Voith E360 or older Woodward CPC units (like the 9907-046) using the same mounting footprint.

Critical Compression: Controlling turbine-driven compressors in chemical processing plants requiring high-availability redundancy.

Installation and Maintenance

Installation

Mounting: Can be mounted in any orientation using four M10 holes. It features the same footprint as legacy CPC units for easy “drop-in” replacement.

Hydraulic Connections: Ensure supply (S), control (C), and return (T) lines are free of burrs. Use high-quality mineral or synthetic oils (20–100 cSt).

Wiring: Use shielded twisted-pair for the 4–20 mA signal to prevent EMI interference in high-voltage turbine halls.

Maintenance

PC Service Tool: Use Woodward’s software via the RS-232 port to perform “Manual Stroke” tests and monitor internal pressure sensor health.

Oil Quality: While the unit is “Dirt Buster” rated, maintaining oil at ISO 20/16 cleanliness levels will maximize the internal valve life.

Visual Status: Check the onboard LEDs: Green for healthy, Flashing for Alarm, and Red for Trip/Fail conditions.

Other Models in the Same Series

Model    Pressure Range    Hazardous Location

9907-1200    0–10 bar (145 psi)    Zone 2 / Div 2

9907-1197    0–25 bar (363 psi)    Zone 1 & 2 / Div 1 & 2

9907-1198    0–25 bar (363 psi)    Zone 2 / Div 2