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We all do it: pump gas. And we probably all have a similar approach as well. We pull into a gas station, swipe a card in the machine, then grab the gas pump and stand beside our car, holding onto the pump as we carefully watch the numbers on the screen go up.

Then, once we’ve gotten hit a pretty shocking price we can afford, we take the pump out, pay, and go on our way.

Photo: flickr/Mike Mozart

But sometimes, we just let our tank fill itself up without bothering to stand guard. And that’s because gas pumps are pretty good at regulating themselves to turn off as soon as our tank is full. But how exactly does the pump know to cut off before gas starts overflowing?

Well, turns out there are mechanisms inside to gauge the fullness of our gas tanks. To get down to the nitty-gritty science of it all was science vlogger and author, Steve Mould.

Photo: YouTube/Steve Mould

Mould is a pretty well-known science enthusiast who makes videos about different things. In order to learn and explain just how a gas nozzle turns itself off automatically, Mould decided to do a little investigating.

This means that he cut up a gas nozzle in order to learn more about its functions, which is a bit complex the way it uses Venturi tubes, levers, and ball bearings – all of which work together to equalize internal pressure within the nozzle when the tank is full. This is what stops it automatically and help to avoid any overflow.

Photo: YouTube/Steve Mould

As he explains, “Gas or petrol pump nozzles turn off automatically when your tank is full. The way it works is really clever and uses the venturi effect.”

Check out the video down below:

Interesting, isn’t it? Did you already know this information about gas nozzles? Let us know!

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