Sphere shelf life?

[noz]

Hi Sean,

My explanation above does not get near the part where the gas laws start to break down. Thats several orders of magnitude away from what I've described. This is simple Boyles Law, Mass Transfer, Osmosis and Permeability Factors, nothing difficult.

Cheers

noz 8)

[JohnW]

Hi all,

Thanks for the replies and your interest in this subject.

Kowalski,

If the LHM was in contact with the Nitrogen, I'd have no doubt about agreeing with you but there is a rubber membrane between the two. I'm not sure whether diffusion of gases through rubber membranes is quite covered by Boyle's writings

Maybe I didn't explain myself well enough. Boyles Law was quoted to emphasise the fact that total pressure is the summation of the partial pressures of all the component gases, nothing more. The movement of gases through a membrane is called the process of 'Osmosis'. (For example, Osmosis is the process by which gases (Oxygen and Carbon Dioxide) are exchanged across a membrane (lungs) in different directions, driven by osmotic pressure.)
Thanks for your replies. Hopefully if we reach a conclusion through reasoned argument we can put to bed some of the more 'flowery' theories which abound on this subject. Thanks.

Cheers

noz 8)

[/quote]

Thanks for this clear discussion - only this morning, discovering a near-dead rear sphere on my Xantia during a little repressurisation project, I was discussing exactly this matter of shelf life and agree totally with your logic. Dealing a bit with RO and permeability matters from day to day helps! Now to find a new sphere or two.......

Cheers

JohnW