Tanks

Hi all,

I've been reading a lot about not being able to get 300 bar air fills, and
this seems to be a reason people give for getting 232 bar tanks.
Is it possible to get a 300 bar tank and only have it filled to 232 bar?

James M

> I've been reading a lot about not being able to get 300 bar air fills, and
> this seems to be a reason people give for getting 232 bar tanks.
> Is it possible to get a 300 bar tank and only have it filled to 232 bar?

Suppose so - just like you can fill a 232 bar tank to 100 bar. I expect the
only difficulty would be with really old compressors which only have
a-clamp, because there isn't an adaptor for it.
From what i've read though, the 300 bar cylinders are heavier than the 232s,
and if you are only filling it to 232 most of the time theres not much point
in carrying the extra weight. I often get 250 bar fills at Stoney anyway,
in a 232 bar tank (although it usually drops to about 240 once its cooled
down), and if (as i've read) a lot of places don't fill to 300 bar but only
280 or so, you really aren't gaining much anyway.

David

"James M" <jrm7262@hotmail.com> wrote in message
news:bo6hfp$l54$1@sparta.btinternet.com...
> Hi all,
>
> I've been reading a lot about not being able to get 300 bar air fills, and
> this seems to be a reason people give for getting 232 bar tanks.
> Is it possible to get a 300 bar tank and only have it filled to 232 bar?
>
> James M
>
>

Yep, but it kinda defies the point of spendng the extra on having a 300bar
tank....

James M wrote:
>
> I've been reading a lot about not being able to get 300 bar air
> fills, and this seems to be a reason people give for getting 232 bar
> tanks. Is it possible to get a 300 bar tank and only have it filled
> to 232 bar?

Naturally. But then you're carrying the extra metal
to withstand the extra pressure for no benefit.
Actually I've never had a problem getting nominal
300bar fills - getting good 300bar fills is another
matter.

Since most divers carry lead the only time the extra
weight is a problem is dragging the things in and out
of the car and if I can do it where's the problem?

nigelH
300bar twin 10s using grandfather

Thank for the reply.

I agree, but hopefully I can get 300 bar fills most of the time.

Also the extra weight may take some lead from my weights.

James M.


"Tricky" <scubatricky@nospamyahoo.co.uk> wrote in message
news:bo6i1h$e3o$1@newsg1.svr.pol.co.uk...
> "James M" <jrm7262@hotmail.com> wrote in message
> news:bo6hfp$l54$1@sparta.btinternet.com...
> > Hi all,
> >
> > I've been reading a lot about not being able to get 300 bar air fills,
and
> > this seems to be a reason people give for getting 232 bar tanks.
> > Is it possible to get a 300 bar tank and only have it filled to 232 bar?
> >
> > James M
> >
> >
>
> Yep, but it kinda defies the point of spendng the extra on having a 300bar
> tank....
>
>

"James M" <jrm7262@hotmail.com> wrote ...

> Don't the A clamp adapter screw ins for 232 bar din valve fit
> in 300 bar din valves?

No they won't, wrong number of threads, that is deliberate to stop you
fitting 232BAR regs to 300BAR tanks. See
http://www.ukrecscuba.org.uk/ukdiver/dinyoke.htm

> Also are 300 bar over fills available ?(ie 310, 320 how high?)

We don't have this quaint US concept of overfills and plus ratings, what's
more we measure the actual tank volume and not the theoretical free air
capacity that so confuses our USA friends

HTH

Keith L

James M <jrm7262@hotmail.com> wrote:
> Don't the A clamp adapter screw ins for 232 bar din valve fit in 300
> bar din valves?

No. Read the link I posted earlier on DIN fittings.

> Also are 300 bar over fills available ?(ie 310, 320 how high?)

Not really. The 232 overfills come from places that can pump 300bar.
At Newhaven our compressor maxes out at 305bar. A good fill means
a fill, leave it to cool and top it off. For a really good fill you
take it out and dump it in the kit rinse tank for ten minutes before
I top it off.

Yes I do overfill home but the kit there could reduce my tanks
to flying metal splinters covered in my blood so I don't go
far over. 775 bar anybody?

You are aware that you're pushing the gas laws at 300 bar? You
don't get as much extra as you hope.
http://www.nigelhewitt.co.uk/diving/maths/vdw.html
I normally reckon my 10/300s hold as much gas as 12/232s but
they are 4L smaller so climbing the ladder after the dive I
am 4Kgs lighter.

nigelH

Hi Keith,

Thanks for the link.
Good info.

james
"Keith Lawrence" <false@nospam.com> wrote in message
news:3fa6df96$0$52881$5a6aecb4@news.aaisp.net.uk.. .
>
> "James M" <jrm7262@hotmail.com> wrote ...
>
> > Don't the A clamp adapter screw ins for 232 bar din valve fit
> > in 300 bar din valves?
>
> No they won't, wrong number of threads, that is deliberate to stop you
> fitting 232BAR regs to 300BAR tanks. See
> http://www.ukrecscuba.org.uk/ukdiver/dinyoke.htm
>
> > Also are 300 bar over fills available ?(ie 310, 320 how high?)
>
> We don't have this quaint US concept of overfills and plus ratings, what's
> more we measure the actual tank volume and not the theoretical free air
> capacity that so confuses our USA friends
>
> HTH
>
> Keith L
>
>

James M <jrm7262@hotmail.com> wrote:

> Yes, the law of diminishing returns applys to high pressure air. I was just
> hoping to get as much air as possible into as small a space as possible. So
> even a few litres extra feels of benefit. Especially in my 3 litre pony.

A 300 bar air pony isn't that much use IMHO. A pony should only be relied upon
as an extra supply in case of emergency so a standard 232 bar pony should
provide you enough air to get to the surface. Yes, a 300 bar pony does weigh
more so you would need less lead but I would say that is a disadvantage as
it would cost more then a 232 bar pony and a lump of lead and make kitting
up harder (assuming that you mount the pony alongside your main tank it will
put you off balance on land whereas putting the weight on a belt wouldn't).

If you're really worried about running out of air then go for a twinset and
forget buying a pony...

Nick

"Nick Bown" <nbown@nospamthanks.ixcg.com> wrote in message
news:3fa77b06$0$12682$fa0fcedb@lovejoy.zen.co.uk.. .
> James M <jrm7262@hotmail.com> wrote:

> If you're really worried about running out of air then go for a twinset
and
> forget buying a pony...

Or you could plan the dive properly

/F