english 
Fuel Tank Anti-Overflow Device
Safety Functions
- Blocks fuel entry at 95% capacity to allow for thermal expansion
- Prevents fire hazards (petrol flash point: -43°C)
- Mitigates vapor explosions (flammable range: 1.3-6% in air)
Critical Safety:
Overflowing fuel creates immediate fire risks near ignition sources like static electricity or vehicle exhaust
Environmental Protection
- Reduces VOC emissions that contribute to smog
- Prevents soil/water contamination from spills
- Complies with EU Stage V and EPA SPCC regulations
Tank Protection
- Maintains vapor-liquid balance (fuel expands ~0.7% per 10°C)
- Prevents damage from excessive pressure (>1 bar)
- Protects EVAP system from liquid fuel flooding
Regulatory Compliance
| Standard | Requirement |
|---|---|
| ISO 9001 | Quality management for automotive components |
| GB 18285 (China) | Vehicle emissions control standards |
| Nozzle shut-off | Automatic activation before full capacity |
Design Mechanisms
- Floater valve: Buoyant float blocks vent tube when full
- Venturi effect: Airflow changes trigger shut-off
- Integrated with pump nozzle pressure sensors
User Considerations
- Avoid "topping off" after automatic shut-off
- Cold weather: Prevents water displacement into fuel stream
- Never override the safety mechanism
Maintenance Tip:
Regularly inspect the filler neck and anti-overflow device during routine vehicle servicing to ensure proper operation