In modern society, refueling nozzles are one of the common tools in our daily lives. However, for many people, how it works and why it automatically jumps from the nozzle not be clear. This article will provide a popular science answer to this question.
1. Refueling nozzles
It mainly consists of three parts: nozzle body, control valve, and metering device.
When the refueler inserts the refueling nozzle into the vehicle’s fuel tank port, the control valve will be opened. At this time, the fuel in the refueling machine begins to enter the vehicle fuel tank through the refueling nozzle.
Secondly, there is a metering device inside the refueling nozzle, which can measure the amount of refueling. Metering devices generally use mechanical or electronic metering.
The principle of mechanical metering is to display the amount of refueling through a needle and a dial,
while electronic metering measures the amount of refueling through a sensor and computer.
Finally, the body of the refueling nozzle is generally made of metal materials,
which have a certain degree of strength and corrosion resistance. At the same time,
there is also an anti-drip device on the top of the refueling nozzle to prevent fuel from dripping from the refueling nozzle.
2. Why can the gun automatically jump after the fuel tank is full?
When the fuel tank is full, the refueling nozzle will automatically jump to avoid fuel spillage. This is a process that utilizes physical principles.
During the refueling process, fuel will enter the fuel tank and a certain amount of steam will be formed in the fuel tank.
When the fuel in the tank has reached a certain level, these vapors will begin to fill the tank. At this time, since the pressure of steam is greater than the gravity of fuel,
the air in the refueling nozzle will be exhausted by the steam.
When the fuel in the tank is nearly full, the oil level is close to the top of the tank, and there is more and more steam in the tank. At this time, because the pressure of the steam is already very high, it is difficult for the air in the refueling nozzle to be discharged. At this time, the control valve of the fuel nozzle will automatically close and stop injecting fuel into the fuel tank. Since fuel is denser than steam, when fuel takes up the tank’s volume, steam is squeezed to the top of the tank. At this time, the air in the refueling nozzle will be affected by pressure, causing some parts of the refueling nozzle to move outward, causing the refueling nozzle to automatically jump.