WOODWARD 9907-1200 CPC-II Current-to-Pressure (I/P) Electro-Hydraulic Converter Valve

Woodward 9907-1200 is a heavy-duty CPC-II series precision current-to-pressure converter specially designed for gas and steam turbine control systems. It receives 4–20mA 

analog control signals output from turbine governors such as Woodward 505, 9905 and other DCS controllers, and linearly converts electric current commands into proportional hydraulic 

pressure output to drive single-acting hydraulic servomotors for throttle valve, inlet guide vane and fuel valve positioning.

Built with integrated hydraulic pilot valve structure and internal feedback mechanism, it realizes closed-loop precise valve position regulation, effectively improving dynamic response and 

positioning linearity of turbine control loops. With robust aluminum alloy housing and internal anti-pollution hydraulic design, it can adapt to contaminated hydraulic oil environments inside 

turbine control cabinets, resisting vibration, temperature fluctuation and electromagnetic interference. It is a core maintenance spare part for overhaul, fault replacement and routine spare inventory 

of thermal power, combined-cycle power plant, petrochemical large compressor turbine control systems worldwide.

Technical Specifications

Part Number: 9907-1200

Manufacturer: Woodward (USA)

Model Series: CPC-II Current-to-Pressure Converter

Input Control Signal: 4–20mA DC standard analog current signal

Output Hydraulic Pressure: Linear proportional to input signal, typical range 0–10 bar

Supply Hydraulic Pressure: Minimum 20 psi, maximum 30 psi supply oil pressure

Overall Accuracy: ±0.2% full span, linearity & hysteresis ≤±0.5% FS

Air/Oil Consumption: 0.5 SCFM @ 20psi supply pressure

Adjustment Function: Built-in zero point and span trim potentiometers for on-site calibration

Operating Temperature Range: -40℃ ~ +85℃

Mechanical Dimension: 358mm × 282mm × 95mm

Net Weight: Approx. 4.13kg

Installation Mode: Panel mounting fixed structure

Hydraulic Oil Compatibility: Compliant with ISO 20/16 oil contamination tolerance standard

Protection Grade: IP65 enclosure protection

Certifications: CE, UL, ATEX explosion-proof certification option

Key Features

High-precision linear conversion characteristic, ensuring highly consistent correspondence between 4–20mA control signal and valve opening, stabilizing turbine speed and load regulation precision.

Fast dynamic response design, effectively suppressing load fluctuation and pressure oscillation during turbine start-up, load ramp and load rejection working conditions.

Independent zero and span adjustment structure, convenient for field on-site calibration without disassembling the whole unit, reducing maintenance operation difficulty.

Internal hydraulic anti-clogging filter structure, strong resistance to hydraulic oil particle pollution, lowering valve stuck and positioning deviation failure rate.

Rugged cast aluminum housing with anti-vibration structural design, adapting long-term continuous operation under harsh vibration environment inside turbine hall cabinets.

Perfect matching with Woodward full-series governors and mainstream turbine control systems, direct replacement for original failed unit without pipeline modification.

Closed-loop internal feedback mechanism eliminates positioning drift caused by oil pressure fluctuation, guaranteeing long-term stable valve positioning repeatability.

Explosion-proof certification optional design, applicable to hazardous area installation requirements of petrochemical and offshore platform turbine units.