air volume formula?

If I have a steel 72 cylinder(working pressure 2200psi)and a steel
85(working pressure 2400psi) both filled to 2200psi which has more air?



Does anyone know a formula for this?

Is there a chart published somewhere?



I've seen several sources that give a cylinder's capacity at full working
pressure, but nothing that would calculate volume at less than full working
pressure as in the case of a steel 85 being filled to only 2200psi.

"." <x@xx.net> wrote in message newsAxmb.30326$iq3.369@okepread01...
> If I have a steel 72 cylinder(working pressure 2200psi)and a steel
> 85(working pressure 2400psi) both filled to 2200psi which has more air?
>
>
>
> Does anyone know a formula for this?

fill pressure/working pressure x size

so

2200/2200 x 72 = 72

2200/2400 x 85 = 77.9166666

Kimber

On Sat, 25 Oct 2003 09:30:52 -0700, "." <x@xx.net> wrote:

>If I have a steel 72 cylinder(working pressure 2200psi)and a steel
>85(working pressure 2400psi) both filled to 2200psi which has more air?
>
>
>
>Does anyone know a formula for this?
>
>Is there a chart published somewhere?
>
>
>
>I've seen several sources that give a cylinder's capacity at full working
>pressure, but nothing that would calculate volume at less than full working
>pressure as in the case of a steel 85 being filled to only 2200psi.
>

If you work in litres and bar it's easy.

Just multiply actual fill pressure (bar) with static volume (litres)
and you have the number of litres of gas squeezed into the cylinder.

It makes comparisons between tanks with different fill pressures and
volumes easy. You could even do it in your head underwater.

Examples:-

10 litre tank with 145 bar, is 1450 litres

12 litre tank with 120 bar, is 1440 litres

7 litre tank with 232 bar, is 1624 litres

Go metric, it's easier. Most of the tech agencies have tests in the
course manuals. Many of the questions about gas mixing and cylinder
volumes become so trivial in metric, it's an embarrassment to ask the
question.

Pete S.

Pete S. wrote:
> Many of the questions about gas mixing and cylinder
> volumes become so trivial in metric, it's an embarrassment to ask the
> question.
>
> Pete S.


.....only if one hasn't had the opportunity to learn.

--
jer email reply - I am not a 'ten' ICQ = 35253273
"All that we do is touched with ocean, yet we remain on the shore of
what we know." -- Richard Wilbur

<Pete S.> wrote in message
news:bd9lpvsmap2sil478psd0l0fs49ddtcmp4@4ax.com...
> On Sat, 25 Oct 2003 09:30:52 -0700, "." <x@xx.net> wrote:
>
> >If I have a steel 72 cylinder(working pressure 2200psi)and a steel
> >85(working pressure 2400psi) both filled to 2200psi which has more air?
> >
> >
> >
> >Does anyone know a formula for this?
> >
> >Is there a chart published somewhere?
> >
> >
> >
> >I've seen several sources that give a cylinder's capacity at full working
> >pressure, but nothing that would calculate volume at less than full
working
> >pressure as in the case of a steel 85 being filled to only 2200psi.
> >
>
> If you work in litres and bar it's easy.
>
> Just multiply actual fill pressure (bar) with static volume (litres)
> and you have the number of litres of gas squeezed into the cylinder.
>
> It makes comparisons between tanks with different fill pressures and
> volumes easy. You could even do it in your head underwater.
>
> Examples:-
>
> 10 litre tank with 145 bar, is 1450 litres
>
> 12 litre tank with 120 bar, is 1440 litres
>
> 7 litre tank with 232 bar, is 1624 litres
>
> Go metric, it's easier. Most of the tech agencies have tests in the
> course manuals. Many of the questions about gas mixing and cylinder
> volumes become so trivial in metric, it's an embarrassment to ask the
> question.

Maybe some day the US will catch up to the rest of the world.

It would improve our math test scores as teachers used to asking how many
inches in a mile ask how many cm in a km and wonder at how smart the kids
are.
Even if this was not a SCUBA forum I'd tell you not to hold your breath.

"Jer" <gdunn@airmail.ten> wrote in message
news:bneb5r$pqj@library1.airnews.net...
> Pete S. wrote:
> > Many of the questions about gas mixing and cylinder
> > volumes become so trivial in metric, it's an embarrassment to ask the
> > question.
> >
> > Pete S.
>
>
> ....only if one hasn't had the opportunity to learn.
>
No, as he said, it becomes trivial after the learning process because it is
so easy to do in your head.

How many ounces in a cubic foot is a valid question on a test and I have to
do the math and probably remember all but useless numbers.

How many cc's in a liter is as close as you can get in the metric system and
the answer is so simple that people would wonder why you asked the question.

How much does a cubic foot weigh if a cubic ounce weighs .5 pounds
How much does a liter weigh if a cc weighs (keeping the weight unit the
same) .5 pounds
You do the math on the first.
I move a decimal point on the second and get 500 pounds in less time than it
takes to type it.

.. left this mess on Sat, 25 Oct 2003 09:30:52 -0700 for The Way to clean up:
>
>If I have a steel 72 cylinder(working pressure 2200psi)and a steel
>85(working pressure 2400psi) both filled to 2200psi which has more air?
>

How stupid are you, and whom should I send my condolences to when you die?

Tao te Carl

"It takes a village to have an idiot." - Carl (c) 2003

Shut the fuck up, ass hole!

--
><(((\">`·.¸¸.·´¯`·.¸.·´¯`·...¸><(((º>¸.
·´¯`·.¸. , . .·´¯`·.. ><(((º>`·.¸¸.·´¯`·.¸.·´¯`·...¸><(((º>

"de Valois" <devalois@nailedandused.com> wrote in message
news:bneou70mf9@drn.newsguy.com...
> . left this mess on Sat, 25 Oct 2003 09:30:52 -0700 for The Way to clean
up:
> >
> >If I have a steel 72 cylinder(working pressure 2200psi)and a steel
> >85(working pressure 2400psi) both filled to 2200psi which has more air?
> >
>
> How stupid are you, and whom should I send my condolences to when you die?
>
> Tao te Carl
>
> "It takes a village to have an idiot." - Carl (c) 2003
>

"Mike Painter" wrote

> Maybe some day the US will catch up to the rest of the world.

Ummm, how's the British space program coming along these days?

Remember the British standard wrenches?

How many pence are there in a pound?

We have been using a decimal system for money for so long it really
surprises me that we haven't long since converted everything to a similar
system.

Lee

On Sun, 26 Oct 2003 15:20:11 GMT, "Lee Bell"
<leebell@ix.remove.netcom.com> wrote:

>"Mike Painter" wrote
>
>> Maybe some day the US will catch up to the rest of the world.
>
>Ummm, how's the British space program coming along these days?

The european programme is doing fine. Ariane. Launches just south of
you guys.

>Remember the British standard wrenches?

You mean British Standard Whitworth? A thread standard. Spanners used
to be sized in the thread size (Whitworth) or AF (across flats) The
ISO series is easier. When we worked in Imperial we had BSW, BSF, UNC,
UNF, BSP(T), BSP(P), BA, Conduit, NPT, and when we were changing over
we had all the metric ones as well. It really is easier now that we
have a set of units that fit together.

>How many pence are there in a pound?

100. There used to be 240.......

>We have been using a decimal system for money for so long it really
>surprises me that we haven't long since converted everything to a similar
>system.

Of course, you couldn't convert to the SAME system could you.........

Pete S.