# How far can we compress air manually?

I am not sure if such devices even exist, but I'm sure we can improvise.

A device in which we could (manually) turn a shaft, screw a screw, or hammer an air-tight follower into a strong walled cylinder, to compress the air that the cylinder holds.

I want real-world figures here. Just how compressed can we get the air? Can we manage to make it liquid with our body muscles?

• "Give me a big enough lever and I will move the world" - apply that to a perfect piston / cylinder combination... – Solar Mike May 15 at 19:44
• @SolarMike Is that Archimedes' quote? Your wording just gave me goosebumps! – El Flea May 15 at 20:08
• This is an engineering site and all engineers know that one... but it should make you think. – Solar Mike May 15 at 20:09
• BTW bicycle pump style pumps are available up to 4500psi. But to liquify air you need low temperature and not just a compressor. – user3528438 May 16 at 21:38

Both solid oxygen and solid nitrogen was already produced in labs.

To create them, you need $$\approx 10 GPa$$ pressure.

No room-temperature liquid phase is mentioned in the articles.

The devices capable to create them, are not cheap. They are driven electrically. Modifying them to use physical human force probably wouldn't be an essential change. But it would be highly impractical, because the price of the electrical energy is a negligible part of the total operating budget.

But yes, such a modified device, we could compress air to solidification with human force.

• Ok, how compressed can we get it without making a money-soaking monstrosity? – El Flea May 16 at 2:19

Tire pump; usually just for bicycles because no one wants to pump enough to fill a auto tire.

• The question makes no reference to volume. I think you've missed the point. – Transistor May 15 at 19:30
• I believe it is a partial answer (we can compress air manually), but it does not answer the realistic maximal reachable pressure with manual devices. Although it is more the fault of the question: there are high compression devices, using probably diamond plates. They are likely electronic, but they could be made even hand-driven, too. It is just un-practical - a device capable to make some hundreds of thousands bars is so costly, that the energy cost is simply a no-issue in it. – peterh - Reinstate Monica May 15 at 20:15
• @peterh-ReinstateMonica Is it that costly? I mean a lever big enough with a piston... is costly? – El Flea May 15 at 20:17
• Yes, a precision diamond compressor, usable for high-pressure R&D, is costly. Believe me, you can not buy it on the ebay for \$5. And the price of the current what it consumes is no-issue in the total operating cost of the lab using it. The lever with the piston can make at most some thousands of bars. Possibly it can be significantly increased by explosives, if the high pressure should be kept only for a very short time, and the partial destruction of the device is allowed. – peterh - Reinstate Monica May 15 at 20:20
• @ElFlea Read this - solid oxygen was made in labs, in 96GPa (about 1million times of the normal pressure). Needless to say, a piston and a level can not do that. – peterh - Reinstate Monica May 15 at 20:26