Description
Product Introduction
The Woodward 37151-01 is a ProAct series electric actuator built for harsh engine and turbine environments. It converts a standard 4–20 mA command signal into precise linear motion to position fuel metering valves or shut-off gates.
This unit handles 200 lbf of continuous thrust. That is roughly 30% more force than the standard 150 lbf ProAct variants. It maintains positional accuracy within 0.5% of full scale across a -40 to 85 °C ambient range.
Key Technical Specifications
| Parameter | Value |
|---|---|
| Supply Voltage | 24 Vdc (18–32 Vdc range) |
| Continuous Thrust | 200 lbf (889 N) |
| Stroke Length | 3.0 in (76.2 mm) |
| Stem Speed (No Load) | 1.5 ips (38.1 mm/s) |
| Control Signal | 4–20 mA (2-wire) |
| Position Feedback | 4–20 mA (active source) |
| Operating Temp | -40 to 85 °C |
| Enclosure Rating | IP56 / NEMA 4X |
| Electrical Connector | 6-pin MIL-Spec (verify connector keying) |
| Duty Cycle | Continuous (S1) |
| Manual Override | Hex shaft, non-clutching |
Woodward 47371-01
Quality Control Process (Engineer’s Perspective)
- Incoming Verification: Check OEM serial number against Woodward shipping docs. Inspect the anodized housing for deep gouges or stripped mounting threads. Look for oil seepage around the stem seal.
- Live Functional Test: Mount the actuator on a test rig. Drive it through full stroke (0–100%) using a calibrated 4–20 mA source. Log response time and check for deadband exceeding 0.3%.
- Electrical Parameter Test: Use a 500 V Megger to verify stator winding insulation >10 MΩ to chassis. Check pin-to-pin continuity on the feedback potentiometer (expect ~135 Ω span).
- Firmware Verification: Read the configuration DIP switches—though your mileage may vary depending on the specific valve linkage. Photograph the switch bank setting before packing.
- Final QC & Packaging: Apply anti-static shrink wrap. Affix a “QC Passed 24hr Run” label with the inspector’s stamp and date.
Replacement Pitfall Guide
❗ Feedback Calibration Drift: Swapping a worn unit for this Woodward 37151-01 often reveals zero-shift. You must mechanically set the zero stop before applying 4 mA, or the valve will sit 5% open.
❗ Connector Pin-Out Changes: Later revisions of the 6-pin plug may shift pin assignments. Always verify the wiring diagram against the tag on the conduit entry, not just the old cable colors.
❗ Supply Current Spike: This 200 lbf unit draws higher inrush current at stall (verify with OEM datasheet, roughly 3 A). Ensure your 24 Vdc PSU has 20% headroom or the breaker trips on stroking.
❗ Manual Override Engagement: The hex shaft override is non-clutching. Forgetting to disconnect the 24 Vdc before hand-cranking can back-feed the drive circuit. Use a lockout tagout.
❗ ESD in Dry Shops: The potentiometer tracks are sensitive. In winter shop air (<30% RH), always use a grounded wrist strap when handling the exposed PCB near the connector.
Keep these in mind and you’ll cut 90% of rework time.
Woodward 47371-01
Compatibility Matrix & Benchmarks
- Woodward 37151-01 → Woodward 37150-01 : Direct — Higher thrust, same mounting
- Woodward 37151-01 → Woodward 37200-02 : Needs Adaptation — Different stroke length (2 in vs 3 in)
- Woodward 37151-01 → Generic 200 lbf Actuator : Incompatible — Signal grounding scheme differs
- Stroke Time: 2.0 s (0–100%, no load, 24 Vdc)
- Position Hysteresis: < 0.25% of span (tested per IEC 534-3)
- Comms Stability: 4–20 mA loop stable to 750 Ω impedance
