High O2 left for long periods...

[DevonDiver]

Originally Posted by Richard Mason

Regs need to be kept wet?

How do we go with brand new regs from the shops? I'll bet that many of them would be several months old before sold. This diving lark is more dangerous than I thought.

Is this really an issue?

New regs haven't been exposed to salt and shouldn't have any moisture in the 1st stage.

However, even with new regs, I'll dive them shallow first until sure about them. I'm not sure of the statistics, but I've heard a few times that there is a higher incidence of failure with new or newly serviced regs.

[nigelH]

What you put in the cylinders is still there.
Gases do not change and they do not settle out.
Go and dive it.

Divers need to be kept wet.

[colinicky]

Most rebreather divers have bailout cylinders that they hopefully never use & I know of people who had their bailouts filled at the time of the test & ran out of test before they were used !

[Midnight]

Originally Posted by Sleepy

Should be OK to use but roll them around the floor for a while to remix the O2 with the air , then re-analise them. I left about 120 bar in a 7L of 82% last year, tested O2 and it had dropped by 4%. Shook it up for a while then retested in the morning, it was back to 82%. Best to check those regs out though.

I think you should get your analyser checked, or just hang the cost and get a new cell. Agree with you about the regs though..... sounds as if they were not rinsed and dried after their last use???

Regards,
Midnight

[scuba steve irl]

the gas would be fine but id get the regs checked

[Adrian Kelland]

Originally Posted by BJ

I left a tank of air for three years and all the nitrogen had settled to the bottom leaving the oxygen at the top (or was it the other way around?). Actually I'm lying. The air around the planet Earth has stayed mixed for millions of years!

That's because of that butterfly that keeps flapping its wings.

[MattS]

Originally Posted by Richard Mason

Regs need to be kept wet?

Heard lots of theories. No idea which if any are correct. I expect it has something to do with the latex oxidising in air, causing it to shrink and perish.

How do we go with brand new regs from the shops? I'll bet that many of them would be several months old before sold. This diving lark is more dangerous than I thought.

I will guess they surface treat the latex with an antioxidant during manufacture. I did once hear an LDS proprietor opine that about 50% of regs shipped would not pass a manufacturers service spec out of the box. Again no idea of any truth in it.

Is this really an issue?

In my experience, yes.

[DIVE BUDDHA]

Originally Posted by Richard Mason

Why?

Would you dispose of the O2 in your club O2 kit after 8 months?

richard firstly im not a member of a club and secondly for the price of o2 its simply not worth keeping the gas if the cylinders are to be used again !

he asked a question and i answered it withg my own opinion !

whether he heeds what hes been told is a different matter !

[g4ssg]

hi
the only reason i can see for the o2 level dropping in a mix ,is oxidation (rusting)
high levels of high pressure o2 will certainly eat through steel in a damp atmostphere ...?how realistic this is in a dry cylinder , not sure...

[scuba steve irl]

oxygen can separate in the gas mix and as oxygen is more dense than air the o2 can separate from the mix .

i did say can .

aggitate the mix roll the cylinder and the mix will "reset"