Eli5: Using Boyle’s law to calculate volume in an oxygen tank

Question

I’m hoping someone can help me understand this concept.

So according to Boyle’s Law, pressure and volume are indirectly proportional
P1V1=P2V2

With that in mind when pressure goes up, volume goes down. Why does the opposite happen when you are decreasing pressure in an Oxygen tank?

I’m thinking it has to do with the release of the gas but is there a different formula that calculates the remaining volume when you are decreasing the PSI on the gauge?

Or am I using the equation incorrectly.

In: Physics

Answer 1

It may help to think of it the other way around. As volume goes down, pressure goes up with a set amount of gas. You’re trying to stuff the same amount of gas into a smaller container, so pressure would increase. Going the other way, if you have a larger container, there is more room for gas to pressure is lower. That doesn’t mean you have less gas, just that there is more space.