On 17/11/2014 17:04, Bald Eagle wrote:
> That's irrelevant once the pressure differential between the two containers is
> equilibrated.  What evaporated into gas can be recompressed back into liquid.
>

Yes, if we ignore heat transfer from the outside it is a closed system.

>> >I dimly remember that refilling a lighter often gave
>> >frustrating results as it was impossible to refill up to the initial
>> >level... with the exception of the use of a/pressurised/  filling mechanism.
>> >
>> >Thomas
> Yes, when refilling with butane the filling container is obviously pressurized.
>
> I believe that there are several interrelated issues here.
>

Nicely observed and the image is handy too.

 > http://www.inpharmix.com/jps/_images/exploded%20lighter%20labeled.jpg

I think that there is an additional factor. As Scott pointed out vapour 
pressure might have something to do with it as well. I did mention but 
it was probably overlooked.
When you fill the lighter the liquid fills the part of the chamber below 
the valve then stops. (Using the image you posted. The central divider 
in the lighter body, is the other way around and the gap is at the valve 
end.) At this point the system is in equilibrium. If you then pour some 
of the liquid into the empty part. You can fill the lighter to a similar 
level in the first chamber.
So I am guessing that it has to do with a function of vapour pressure 
and the distance from the top of the liquid to the inlet valve.


-- 

Regards
     Stephen

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