Why is Air in Pneumatic Cylinders Pressurized so High?

[El Moriana]

Hi there,

My thermodynamics textbook shows the critical pressure of Air to be 37.7 bar. Why is it, then, that pneumatic cylinders are pressurized to pressures like 300 bar? If the air is already a liquid and liquid is near incompressible, what is the point of pressurizing it so much if you can't fit much more air in?

 

[Deric Boyle]

It liquify at critical temp. only.In neumatic pistons the temp. is much above the critical value

 

[El Moriana]

Ah. Of course . thanks

 

[kluvsoccer]

Hi there,

My thermodynamics textbook shows the critical pressure of Air to be 37.7 bar. Why is it, then, that pneumatic cylinders are pressurized to pressures like 300 bar? If the air is already a liquid and liquid is near incompressible, what is the point of pressurizing it so much if you can't fit much more air in?

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What is the definition of compression of air molecules?

 

[Deric Boyle]

Dear kluvsoccer who told you that we can compress air molecules :-) .
As per quantum what I believe is that no atom or molecule have well defined boundary.We only talk in relative terms that is covalent, ionic or van der Wall