Key Technical Specifications
- Product Model: 9907-1200
- Manufacturer: WOODWARD
- Product Type: Electrohydraulic Converter (CPC-II)
- Input Signal: 4-20 mA Current Demand
- Max Control Pressure: 10 Bar
- Fluid Cleanliness: ISO 20/16 Tolerance
- Mounting Interface: 4x M10x1.5 Bolts
- Hydraulic Ports: S (Supply), C (Control), T (Tank)
- Self-Cleaning: Integrated Valve Algorithm
- Diagnostics: Status LEDs, Health Indicators
Product Introduction
WOODWARD 9907-1200 is a second-generation electrohydraulic converter designed to position single-acting steam turbine valves. It translates a 4-20 mA control signal into precise hydraulic pressure for servo actuators.This CPC-II unit solves fluid contamination issues common in older systems. It features an internal self-cleaning algorithm and accepts ISO 20/16 oil, reducing downtime caused by particulate buildup.
Installation & Configuration Guide
Preparation (10 min)
Isolate hydraulic supply. Depressurize the servo line. Clean the adapter block mating surface. Inspect O-ring grooves for nicks. (A scratched groove will leak at 10 bar.)Removal (5–10 min)
Disconnect electrical harness. Remove four M10x1.5 bolts. Pull unit straight off adapter block. Cap hydraulic ports immediately to prevent contamination.Installation (10 min)
Place new O-rings in adapter block. Seat unit flush. Torque M10 bolts to 60-80 N·m in cross pattern. Connect S, C, and T lines per diagram. Reconnect 4-20 mA signal.Power-On & Test (10 min)
Apply 24V DC. Check status LEDs. Command 4 mA; verify zero pressure. Command 20 mA; verify 10 bar output. Watch for hunting or oscillation. If unstable, check gain settings.
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| No Pressure Output | No Input Signal | Measure 4-20 mA at terminals; verify 24V supply |
| Pressure Won’t Reach 10 Bar | Clogged Filter | Replace upstream filter; run self-clean cycle |
| Erratic Valve Position | Air in Lines | Bleed hydraulic circuit; check for cavitation |
| Red LED Lit | Internal Fault | Read diagnostic code via service tool |
| External Leak | O-Ring Failure | Replace face-seal O-rings; re-torque bolts |
Dimensions, Mounting & Wiring Notes
- Mounting: 4x M10x1.5 bolts, 16mm min thread engagement
- Hydraulic Ports: S, C, T with face-seal O-ring interface
- Recommended Hose ID: 18mm (min 12mm)
- Orientation: Ports-down preferred for dirty oil
- Clearance: Allow space for top cover removal and LED viewing
FAQ
Can I mount this in any orientation?
Technically yes, but ports-down is recommended if your oil has water or particulate. Gravity helps drain contaminants away from the valve spool.I’m getting oscillation. Is the unit bad?
Check your tuning first. The 9907-1200 has adjustable gain. Also verify there’s no air trapped in the servo line. Air compresses and causes hunting.Do I need a special adapter block?
Yes. The 9907-1200 mounts to an adapter plate that routes S, C, and T ports. The plate must have face-seal O-ring grooves. Don’t use pipe-thread fittings directly.What oil cleanliness level does it need?
ISO 20/16 or better. This unit is more tolerant than older designs, but clean oil still extends life. Install a 5-micron filter upstream.How do I read the diagnostic LEDs?
Green = healthy. Red = fault. Flash patterns indicate specific issues like sensor failure or power loss. Check the CPC-II manual for the exact code table.Is this compatible with my old CPC-I system?
Mechanically similar, but electrically different. CPC-II uses different signal conditioning. Verify your controller output matches 4-20 mA spec before connecting.Can I rebuild this myself?
Not recommended. The self-cleaning valve has tight tolerances. Factory rebuild includes calibration and seal replacement with OEM specs. Field repairs often cause leaks.
