I. Product Overview

9907-1200 = CPC-II Single - a single model electro-hydraulic converter, original factory product of Woodward, USA. It converts 4-20mA electrical control signals into linear hydraulic control oil pressure, driving the main regulating valve oil motor of a steam turbine. It is the core conversion component of the electrical-to-hydraulic control system for steam turbine regulation systems, and is an upgraded replacement for the old CPC-I series (9907-1100/1102/1103/1105/1106, 8901-457/459).

Core Technical Parameters

1. Electrical Parameters

Analog Input: Isolated 4-20mA DC (250Ω input impedance, 4mA = zero oil pressure, 20mA = full pressure), supporting dual main/standby redundant input

Power Supply: DC18-32V (rated 24VDC), steady state 1.5A, peak 8A (100ms short time)

Communication: Onboard RS232 debugging port, dedicated Woodward Service Tool software for zero point/range calibration, fault reading

Fault Indicator Lights: Three-channel status LED self-check display for power supply, input signal, and built-in oil pressure sensor

2. Hydraulic Parameters (standard 0-10bar model, mainstream on the market)

Output Control Oil Pressure: 0-10bar (0-145PSI), linearly following 4-20mA; optional 0-2bar low-pressure customized version

Supply Pressure: 3.5-10bar of clean anti-wear hydraulic oil, oil product tolerance ISO20/16 contamination level, superior to the first-generation CPC anti-blocking performance

Oil Ports: 3 standard hydraulic interfaces (P inlet, T return, S control outlet connected to servo cylinder)

3. Accuracy and Dynamics

Full-scale linear error: <±0.2% FS, repeatability ≤0.1% FS, temperature drift ≤0.01%/℃

Response Time: Full travel response <100ms, built-in oil pressure closed-loop PID, supply pressure fluctuations do not affect the stability of output oil pressure

4. Physical & Environmental

Dimensions: 356×279×102mm (14×11×4inch), net weight ≈4.13kg (without hydraulic oil)

Protection: IP56/IP66, cast aluminum shell, explosion-proof ATEX Zone1 certification, SIL2 safety certification, CE, UL

Operating Temperature: -40℃ to +85℃, can be installed in any position (vertical/horizontal), base M10 installation screw holes

Key Product Features

Built-in Closed-loop Oil Pressure Feedback: Equipped with a high-precision built-in pressure sensor for real-time sampling and outputting oil pressure, closed-loop stabilization, eliminating the drift of the regulating valve caused by supply pressure fluctuations;

On-site Hardware Fine-tuning: The body is equipped with Zero zero point, Span range fine-tuning screws, without disassembling the hydraulic pipeline, it can be directly calibrated to the 4-20mA-oil pressure curve;

Power Failure Safety Protection: When power is lost or signal is disconnected, the built-in reset spring automatically releases pressure, returning the control oil to the oil tank, ensuring the safety shutdown of the regulating valve (fault loss of oil protection);

Anti-contamination Valve Core Structure: Improved throttling valve orifice, the failure rate of the poor-quality turbine oil in power plants is much lower than the first-generation CPC-I.

Supporting Control System & Application Scenarios

Matching Speed Governor

Standard Connection: Woodward 505/505E, PEAK150, EGCP-3 steam turbine speed governor, can also directly receive 4-20mA analog output from DCS system.

Applicable Industries

Self-owned power plants / thermal power: Small and medium-sized back-pressure, extraction industrial steam turbine main steam valve servo control;

Refining and oil industry: Catalytic cracking fan, steam turbine, expansion machine speed regulation system;

Steel mill waste heat power generation, biomass steam turbine unit, gas turbine steam bypass valve control. V. Differentiation of the Same Series Models

9907-1200: Simplex single machine type (standard 10bar, main stock item)

9907-1201: Dual redundant coil model (for critical units, one control with dual backups)

9907-1202: Special model for low pressure 0-2bar output (for small-sized servo with short stroke)