Description
Key Technical Specifications
| Parameter | Specification |
|---|---|
| Manufacturer | Woodward |
| Model | 9907-1106 |
| Product Family | CPC-II |
| Product Type | Current-to-Pressure Converter |
| Command Input | 4–20 mA |
| Control Pressure Range | 0–10 bar / 0–145 psi |
| Maximum Supply Pressure | 25 bar / 363 psi |
| Maximum Tank Pressure | 2 bar, or 30% of minimum control pressure, whichever is lower |
| Maximum Flow Capacity | 2 L/min at 25 bar inlet pressure |
| Area Classification | Class I, Division 2; ATEX Zone 2 |
| Enclosure Rating | IP56 |
| Hydraulic Valve | Rotary 3-way hydraulic valve |
| Actuator | Brushless limited-angle rotary actuator |
| Feedback | Internal pressure sensing |
| Application | Steam/fuel valve and servo-system positioning |
Woodward’s CPC-II documentation confirms the 9907-1106 pressure range, supply rating, area classification, and converter construction.
Application Scenarios & Pain Points
A turbine trip caused by a control-pressure problem is expensive even when the underlying component is relatively small. Before condemning the governor, engineers should verify the complete chain: command signal → CPC-II → hydraulic pressure → servo → valve position.
9907-1106
Typical Applications
- Steam Turbines: Used to regulate hydraulic control pressure for steam admission/governor valve positioning. The 4–20 mA command is translated into proportional hydraulic output.
- Fuel Valve Control: Applicable to systems where a proportional electrohydraulic signal is required to position fuel-control valves or associated actuators.
- Turbine Retrofit Projects: 9907-1106 can replace older Woodward CPC models 8901-455, 8901-457, and 8901-459 when the application matches the specified pressure range and area classification.
- Legacy Control-System Maintenance: Particularly useful when an older CPC installation needs to remain in service without redesigning the complete hydraulic control circuit.
Field Case:
On a turbine with unstable valve positioning, a useful diagnostic sequence is to verify the governor’s 4–20 mA command first, then measure CPC-II hydraulic output independently. If the electrical command is stable but control pressure hunts, the investigation can move toward the converter, oil cleanliness, pressure feedback, or hydraulic circuit rather than immediately replacing the governor.
Related Products
- WOODWARD 9907-1103 — CPC-II version with the same 0–10 bar control-pressure range but intended for more demanding hazardous-area classifications, including Class I Division 1 and ATEX Zone 1/Zone 2 applications. It is not a casual substitute for 9907-1106; the site certification requirements must match.
- WOODWARD 9907-1102 — CPC-II model for a 0–25 bar control-pressure range and Class I Division 2 / ATEX Zone 2 applications. Select this only when the hydraulic control system requires the higher pressure range.
- WOODWARD 9907-1100 — 0–25 bar CPC-II version for higher hazardous-area requirements, including Class I Division 1 and ATEX Zone 1/2 configurations.
- WOODWARD 9907-1200 — CPC-II Enhanced replacement associated with the 9907-1106 configuration. Woodward identifies it as the enhanced-dynamics counterpart for the 0–10 bar, Zone 2 configuration.
- WOODWARD 9907-1199 — CPC-II Enhanced alternative associated with the 9907-1103 0–10 bar hazardous-area configuration. It is more appropriate where the original installation requires the higher area-classification rating.
- WOODWARD 8901-455 — Older CPC generation that Woodward lists among the units replaceable by CPC-II 9907-1106 in appropriate applications.
- WOODWARD 8901-457 — Legacy CPC model included in the 9907-1106 replacement group. Verify the existing hydraulic range and hazardous-area requirements before conversion.
- WOODWARD 8901-459 — Another older CPC model for which Woodward documents 9907-1106 as the CPC-II replacement.
- WOODWARD 8928-7240 — Adapter kit used when replacing a Voith E360 I/H converter with a CPC-II. This is installation hardware rather than an alternative converter.
