Key Technical Specifications
- Product Model: 8402-271
- Manufacturer: WOODWARD
- Product Type: Solenoid Actuator / Fuel Valve
- Operating Voltage: 24 VDC
- Valve State: Normally Closed (NC)
- Response Time: < 50 ms (Trip)
- Flow Medium: Fuel Oil / Gas
- Pressure Rating: Up to 150 PSI
- Coil Power: 25W Max
- Mounting: SAE Flange / Direct Bolt
Product Introduction
WOODWARD 8402-271 is a high-speed solenoid valve used in turbine fuel systems for emergency shutoff and load control. It provides reliable, fail-safe fuel isolation when de-energized.This unit features a low-friction spool design and optimized magnetic circuit for consistent trip times. Field experience shows coil insulation breakdown is the primary failure mode after 10+ years of service.
Installation & Configuration Guide
Preparation (10 min)
Isolate fuel supply. Depressurize downstream line. Lock out electrical power. Clean mounting flange. Inspect gasket surface for grooves. (A scored flange will leak fuel under pressure.)Removal (5–10 min)
Disconnect 24VDC leads. Remove mounting bolts. Pull valve off adapter. Cap fuel ports immediately. Tag wires if multiple valves are present.Installation (10 min)
Install new gasket or O-ring. Seat valve flush. Torque bolts evenly. Connect 24VDC leads with correct polarity. Verify fuel direction arrow matches flow.Power-On & Test (10 min)
Apply 24VDC. Valve should open. Remove power; valve must close within 50 ms. Check for external leaks at flange and coil housing. Listen for chatter (indicates low voltage or debris).
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| Valve Won’t Open | No 24VDC at Coil | Measure voltage at terminals; check fuse |
| Slow Trip Time | Coil Weak / Debris | Measure coil resistance; inspect for metal particles |
| External Leak | Gasket Failure | Replace gasket; check flange flatness |
| Coil Overheating | Wrong Voltage | Verify 24VDC ±10%; check for AC ripple |
| Chatter / Buzz | Low Voltage or Air | Check power supply; bleed air from fuel line |
Dimensions, Mounting & Wiring Notes
- Mounting: SAE flange or 4-bolt pattern
- Electrical: DIN connector or flying leads
- Fuel Ports: SAE O-ring boss or NPT (verify)
- Clearance: 50mm min above coil for heat dissipation
- Orientation: Coil vertical preferred; horizontal OK if fuel is clean
FAQ
Is this valve normally open or closed?
Normally closed. It opens when 24VDC is applied and closes on power loss for fail-safe operation.Can I use 12VDC on this coil?
No. The coil is wound for 24VDC. Lower voltage will cause slow opening and overheating. Higher voltage will burn it out.My valve trips slow. Is it worn?
Possibly. Measure coil resistance first. Then check for debris in the spool bore. A 5-micron particle can cause sticking.Do you test the trip time?
Yes. Every 8402-271 is tested on a fuel bench for response time and leak-tightness. Test data is included.What’s the expected life?
Typical service life is 10-15 years or 500,000 cycles. Coil insulation is usually the first thing to fail in hot environments.Can I replace just the coil?
Yes, if the spool and body are undamaged. But verify the coil part number matches exactly. Wrong coil = wrong force.I smell fuel at the coil. Is that normal?
No. That indicates an internal seal leak. Stop using it immediately. Fuel in the coil cavity is a fire hazard.
