Why does the fuel nozzle click off during refueling?

[ORicardo]

The design principle of the gas station fuel nozzle is actually quite simple. It clicks off because when the fuel reaches a certain level, combined with the pressure and air in the tank reaching a certain amount, it automatically triggers the switch in the nozzle, causing it to click off. No Smoking: "No open flames" is a common warning seen everywhere at gas stations. For those who have the habit of lighting up a cigarette while parked, this habit must absolutely not be brought to the gas station. This is because the concentration of gasoline in the unit space increases during refueling, and an open flame could potentially ignite the gasoline. Turn Off the Engine: It's essential to turn off the engine while refueling, a practice most car owners are aware of. Every time you drive into a gas station, the staff will remind you to turn off the vehicle. However, at some self-service or smaller gas stations, instances of refueling without turning off the engine have indeed been observed.