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"Right, done the pool stuff, what's next.........?
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<font color='#000080'>There was a thread regarding the cost of decanting set ups that I can't find at the moment.
Has anybody made or tried to make a decanting hose from a buddy remote valve. I mean the kind from the pioneer jacket.
If you have a spare first stage knocking about and you have a jacket and don't use the bottle seems to me you have most of the bits that you will need.

I've not tried it yet so if anybody can see a reason not to,especially a safety one, please say so now. John.
 

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Shipwrecked & Comatose, drinking fresh mango juice
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<font color='#810541'>this may sound a bit mad, but based on what Mark Chase recommended (i.e. filling one half of a twinset with a whip) then it must be possible to decant from a full cylinder to a twinset via a buddy emergency cylinder?

so, twin 10's breathed down to 100 bar, spare (full) 15l at 232 bar.  The manifold is turned off on the twins at the start .......

assuming the buddy emergency cylinder is empty at the start, decant from the 15l to the little cylinder .......

232 bar @15l = 3480l air divided by volume of 15l plus the buddy cylinder (say, 0.4l) = 226bar.

close the valves and transfer buddy cylinder to one half of twin 10s ......
100 bar in a 10l - 1000l of air, plus 226 bar in the 0.4l buddy cylinder = 90l.  1090l of air in a 10.4l join capacity gives an overall pressure of ...... 104.8 bar.

Start the process over again and keep going.  So the problem of what do do during the surface interval is solved.  I'm sure I could work out on a spreadsheet how many times it would take to transfer maximum pressure to one side of the twins and what that max pressure would be but I'm not sure I could be bothered.

god, this Friday is going on forever isn't it.
 

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I got a decanting setup for about £50 from Kent Diving, I think
 

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"Right, done the pool stuff, what's next.........?
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<font color='#000080'>Hi Beanie, after you unscrew the hose from the buddy bottle you will need someway of connecting it to your cylinder to decant from it.
So you end up with, a first stage, the buddy hose which has an A clamp fitted already fitted. I've had a look and the connection on the buddy hose is high pressure which when you think about it thats how you fill the cylinder on the jacket so it has to be.
Get the feeling I'm not making sense here. John.

I'm not saying use the cylinder from the jacket we get rid of that, just use the hose and connector that is on it.
 

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<font color='#8D38C9'>you need a connector to replace the bottle in essance which would have to be another ap valves emergency cylinder valve

AP do a decanting whip DIN-DIN 2m for <£100 no good for blanding but fine for decanting

mind you if you can get one for £50 even better
mine was prob about £250 new I paid 150 second hand
 

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Shipwrecked & Comatose, drinking fresh mango juice
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<font color='#810541'>
[b said:
Quote[/b] (aclivity @ Mar. 19 2004,16:47)]this may sound a bit mad, but based on what Mark Chase recommended (i.e. filling one half of a twinset with a whip) then it must be possible to decant from a full cylinder to a twinset via a buddy emergency cylinder?

so, twin 10's breathed down to 100 bar, spare (full) 15l at 232 bar.  The manifold is turned off on the twins at the start .......

assuming the buddy emergency cylinder is empty at the start, decant from the 15l to the little cylinder .......

232 bar @15l = 3480l air divided by volume of 15l plus the buddy cylinder (say, 0.4l) = 226bar.

close the valves and transfer buddy cylinder to one half of twin 10s ......
100 bar in a 10l - 1000l of air, plus 226 bar in the 0.4l buddy cylinder = 90l.  1090l of air in a 10.4l join capacity gives an overall pressure of ...... 104.8 bar.

Start the process over again and keep going.  So the problem of what do do during the surface interval is solved.  I'm sure I could work out on a spreadsheet how many times it would take to transfer maximum pressure to one side of the twins and what that max pressure would be but I'm not sure I could be bothered.

god, this Friday is going on forever isn't it.
it was a stupid idea, but I worked it out anyway (working on a spreadsheet = gives the impression of being hard at work)

I reckon it would take 60 'cycles' of decanting via the buddy cylinder to get within 5% of the pressure you would get by decanting directly.  Upi can keep on going forever (according to my spreadsheet model) but the returns diminish probably beyond what is measurable.

However, it did make me think - doing it a couple of times makes sense:

15l ar 232 bar decanting directly into one half of a twin 10 at 100bar:

15 x 232 = 3480l
10 x 100 = 1000l
total gas volume = 4480l
divide by combined cylinder volume (25) = 179.2

Open manifold at this stage ....

(10 x 179.2) + (10 x 100) = 2792l
divided across 2 cylinders - 139.6 bar in both

close manifold

15 x 179.2 = 2688l
10 x 139.6 = 1396l
total gas volume = 4084l
divide by combined cylinder volume (25) = 163.36

do the decant process 3 times and the pressure in the twinset will be 155 bar.  After 3 times the increase drops off dramatically.  I can provide my spreadsheet if anyone wants it?
 

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Guess who's got a buddy cylinder, hose and old first stage knocking about  


Just a bugger the twins are 300 bar  


Daz
 
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