The Woodward 9907-1106 CPC-II (Current-to-Pressure Converter, Generation II) is a high-precision, electrohydraulic pressure-regulating valve control designed for positioning single-acting steam turbine valve servos. By converting an isolated 4–20 mA electrical demand signal into a highly stable and proportional hydraulic output pressure, it enables exceptionally accurate speed and load regulation while minimizing mechanical wear across the governor valves.
The 9907-1106 model is specifically configured for high-pressure operations up to 25 bar (363 psi) with an adjustable control output pressure range of 0 to 10 bar (0 to 145 psi), making it a critical asset for robust power generation and industrial processing systems.
Product Specifications
Technical Parameters
- Model Designation: CPC-II (Generation II)
- Part Number: 9907-1106
- Manufacturer: Woodward
- Primary Input Setpoint: Isolated 4–20 mA (250 Ω input impedance)
- Secondary/Redundant Input: Isolated 4–20 mA (Configurable for redundant setpoint or external feedback)
- Maximum Hydraulic Supply Pressure: 25 bar (363 psi)
- Maximum Output Pressure Range: 0 to 10 bar (0 to 145 psi)
- Control Accuracy: < ±0.2% of full scale
- Repeatability: 0.1% of full scale
- Total Response Time: 10 to 30 ms (Scan time of 2.5 ms)
- Pressure Stability: < ±2% of set value
- Hysteresis: < 0.08% of span
Electrical & Communication
- Supply Voltage: 18–32 VDC (1.5 A steady-state, 8 A peak for 100 ms)
- Analog Output Signal: 4–20 mA (Maximum external load 300 Ω, ±1% FS accuracy)
- Discrete Inputs: Optically isolated (Requires 24 VDC wetting voltage)
- Discrete Outputs: 2 channels rated at 1 A @ 30 VDC (Configurable for alarms/trips)
- Service Port: RS-232 serial communication interface for PC software calibration
Physical Datasheet
- Dimensions (W×H×D): 290mm x 270mm x 270mm
- Weight: 25 kg (55 lbs, dry)
- Housing Material: Anodized aluminum with a 4-bolt end face seal
- Valve Mechanicals: 440C stainless steel bushing and rotary shaft layout
- Ingress Protection: IP56 (according to IEC/EN 60529)
Application Fields
The 9907-1106 CPC-II is engineered for high-availability steam turbine operations:
- Power Plants: Regulating primary governor and throttle valves on steam turbines for grid frequency stabilization.
- Petrochemical Refineries: Managing valve positioners on high-load extraction or induction turbines.
- Marine Propulsion: Controlling the main steam intake on large electric or mechanical drive vessels.
- District Heating Networks: Handling localized steam-by-pass control valves during sharp plant transients.
Product Usage Instructions
- Mechanical Mounting: Secure the device using four M10×1.5 bolts with a minimum of 16mm thread engagement. Tighten bolts to a torque specification of 60–80 N·m. The unit shares the same footprint as legacy CPC units for drop-in replacement.
- Hydraulic Integration: Connect the supply-oil, control-oil, and return-drain lines using standard Woodward manifold adapter blocks. Ensure the return line internal diameter is at least 18mm to maintain a low drain pressure (≤ 2 bar).
- Contamination Defense: The CPC-II features patent-pending “Silt Buster” and “Dirt Buster” technology capable of shearing through particles up to 40 μm. However, installing a 24–40 μm high-capacity upstream filter (ISO 20/16 recommended) ensures long-term operational longevity.
- Wiring and Shielding: Route analog 4–20 mA connections through shielded twisted pairs. Pass the shield grounds through designated internal decoupling capacitors to mitigate high-frequency ground loops and EMC interference.
- Failsafe Mechanics: In the event of a catastrophic system error (such as a drop in 24 VDC logic power or internal processor lock), an internal, mechanical spiral return spring forces the rotary valve to a fully open bypass position, safely draining control oil to close the turbine governor valve immediately.
Q&A – Frequently Asked Questions
Q: Can the 9907-1106 handle dirty turbine lubricating oil? A: Yes. One of the primary engineering upgrades of the CPC-II over the first generation is its robust high-force actuator (4x stronger) and self-cleaning rotary ports, specifically designed to function reliably without sticking in contaminated oil conditions.
Q: What is the main difference between the 9907-1106 and the 9907-1102? A: While both are Generation II units, the 9907-1106 regulates an output range of 0–10 bar (145 psi), whereas the 9907-1102 regulates a higher output range of 0–25 bar (363 psi).
Q: How is the valve calibrated or linearized? A: Configuration is completed via the PC-based Woodward Service Tool software over the RS-232 serial link. The tool provides an 11-point valve linearization table to match the specific characteristics of your hydraulic servo cylinder.
Q: Where can I obtain a quote, check inventory, or find an official user manual? A: For commercial pricing details, immediate international delivery windows, and certified product certifications, please contact us via our Woodward CPC-II 9907-1106 Procurement Portal.
Product Related News
In mid-2026, industrial facility managers continue to prioritize the Woodward CPC-II 9907-1106 as a preferred “MRO Upgrade asset” to replace obsolete electrohydraulic converters, such as the original CPC series and Voith E360 units. As modern processing centers optimize their internal digital control infrastructure, the CPC-II’s built-in advanced diagnostics and performance-trending software tools allow control rooms to monitor real-time oil pressure latency. This capability enables operators to implement predictive maintenance workflows, identifying subtle actuator friction changes before an unexpected trip can happen. The unit’s ATEX Zone 1 and Zone 2 certifications ensure it complies with the latest European and North American explosive-atmosphere safety regulations for hazardous environments.
