Products Description
Description
The Woodward 9907-1199 is a CPC-II (second-generation Current-to-Pressure Converter) model built for Zone 1/Zone 2 hazardous locations. It converts a 4–20 mA control signal into a stable 0–10 bar (0–145 psi) hydraulic pressure to position single-acting steam turbine valves with high precision. From my experience, the 9907-1199 is chosen when you need reliable valve positioning in explosive atmospheres without constant filter fuss or creeping drift.
Key Features
Hazardous-area ready (Zone 1 & Zone 2) – Designed for Ex-rated steam turbine environments where Class I/Zone compliance is mandatory.
4–20 mA to 0–10 bar conversion – Directly positions single-acting governor/stop valves with a proportional pressure output.
High accuracy and repeatability – Typically ±0.2% FS accuracy and 0.1% repeatability help maintain stable turbine operation.
Fast response – Sub‑75 ms (to 90% of span) response supports tight control during load changes.
Silt Buster contamination relief – The patented feature dislodges ~40 μm debris, often reducing external filter service.
Robust diagnostics – Health/status indication, alarm outputs, and a service port (RS‑232) for commissioning and monitoring.
Redundancy options – Supports redundant pressure demand inputs and configurable main/standby control logic.
Fail‑safe behavior – On power loss or serious fault, it’s designed to drive the valve to a safe state.
IP66 enclosure – Weatherproof construction for field mounting, any orientation.
ｄｒｏｐ‑in upgrade path – In many cases replaces older hazardous CPC units (e.g., 9907-046) using the same base and ports.
Technical Specifications
Brand / Model | Woodward 9907-1199 (CPC‑II) |
HS Code | 9032.89 (Automatic regulating or controlling instruments, other) |
Power Requirements | 18–32 V DC; approx. 2 A continuous @ 24 V; up to ~8 A peak for short durations (startup/transients) |
Signal Input / Output | Input: 4–20 mA (isolated, ~250 Ω). Discrete inputs: opto‑isolated, nominal 24 V DC. Outputs: Hydraulic 0–10 bar; Discrete 1 A @ 30 V DC; Analog 4–20 mA (max ext. load ~300 Ω). |
Communication Interfaces | RS‑232 service port for setup and diagnostics |
Output Pressure Range | 0–10 bar (0–145 psi); accuracy typically < ±0.2% FS; repeatability 0.1% FS; hysteresis < 0.08% FS; response < 75 ms (90%) |
Hydraulic Ports | S (Supply), C (Control), T (Return); recommended oil 20–100 cSt, supply ~10 bar; return ≤ 2 bar |
Dimensions & Weight | Approx. 290 × 270 × 270 mm; ~25 kg (dry) |
Operating Temperature | ‑40 °C to +85 °C ambient; hydraulic oil 15–70 °C typical |
Protection & Rating | IP66 enclosure; EMC per EN 61000‑6‑2 |
Hazardous Location | Zone 1/Zone 2 (Ex d T4) and Class I, Div. 1/2 T4, model‑specific approvals |
Installation Method | Field mount in any orientation; 4 × M10 threaded holes (approx. 23 mm depth); conduit sealing as per zone rules |
Application Fields
Steam turbine valve positioning in refineries, petrochemical complexes, and power plants
Zone 1/Zone 2 hazardous areas where explosive gases may be present continuously or intermittently
Upgrades of legacy hazardous CPC units with minimal mechanical rework
Critical control systems requiring high availability and SIL‑aligned architectures
You might notice that it excels where oil quality isn’t always perfect. The Silt Buster feature seems to keep the control stage clean enough to avoid nuisance sticking, which—according to one turbine maintenance lead we worked with—cut their filter changes by half during a peak season run.
Advantages & Value
Reliability – Stable pressure output reduces valve wear and improves speed/load stability.
Compatibility – 4–20 mA command, RS‑232 service access, and standard S/C/T hydraulic ports fit most retrofit jobs.
Cost Savings – Fewer filter interventions and quicker commissioning typically trim outage time and labor.
Risk Reduction – Certified for hazardous areas with fail‑safe behavior and robust diagnostics.
Upgrade Path – Direct replacement for older hazardous CPC models (e.g., 9907-046) with performance gains from linearisations and improved contamination tolerance.
Installation & Maintenance
Mechanical
Mount using 4 × M10 bolts; engagement ≥ 16 mm; typical torque 60–80 N·m.
Install adapter block if required and flush all hydraulic lines before hookup.
Connect hydraulic ports S (supply ~10 bar), C (control), and T (return ≤ 2 bar). Keep oil within 20–100 cSt viscosity.
Enclosure is IP66; ensure drip loops and strain relief in outdoor layouts.
