[Alan57]

John
I too found the Haskel solution too expensive. However I recently took receipt of a Jetsam nanobooster from Canada. This ideal for pumping Inspiration 3l bottles with any gas. If you are an engineering type you can by the basic pump. I'm not so bought complete including guages and case for about £1250 . Exchange rates are now better = cheaper. I've copied his standard enquiry email below including technical stuff you'll probably understand.
Quote:
Standard info below.
The basic dimensions of the gas driven booster are 110mm X 110mm X 300mm.  The prototype weighs 3.2 Kg. without whips.

The first 50 are sold, but don't worry. I'll make more.

The pumping rate is a bit complicated with a pneumatic booster. The ratio between the drive piston and the output piston is 23:1. In theory a 10 bar drive gas will yield a 230 bar output. In fact the seal friction and the gas compressibility reduces the output to around 210-220 bar. The effective boost  ratio between the supply tank and the output tank can be as much as 5:1 ( 3:1 with helium ). So you could pressurize a tank to 200 bar from a supply tank at 40 bar. In practice you would use far too much drive gas to make it practical.  From what I have seen a 3:1 ratio is more realistic. When the supply tank pressure drops below 75 bar the drive gas consumption becomes excessive if you are using a scuba tank to drive the booster. Other variables are the relative size of the supply and fill tanks.

The drive piston displaces .29 liters per stroke. The output piston displaces .0126 liters. So a 12 liter scuba tank should provide almost 800 strokes at maximum outlet pressure. Inlet and outlet ports are 1/4 female npt.

As an example:

To fill a 2 liter tank which was at 170 bar to a final pressure of 210 bar from a 12 liter supply tank that had 110 bar of air took three minutes and 52 strokes of the booster. To fill a 2 liter tank from 100 bar to 210 bar from a 12 liter tank that had 100 bar took 10 minutes and 165 strokes.

If you want fill whips or other options the prices are below. If you already have whips you will just need to adapt to the booster ports.


Booster........................$1250.00 US
2 DIN 200 Bar bleeders..... 190.00
Line valve...........................45.00
2-60" (1.5m).................... .166.00 (Swagelock SS/Teflon hoses)
Fittings...............................75.00
Gage..................................50.00 (2.5" 0-5000psi & 0-350 kpa)
Pelican 1500 case.......... ..125.00
Shipping...........................150.00

I'm not set up for credit cards or Pay Pal. Money order, bank draft, or wire transfer. Whatever is easier.
End quote.
Hope this helps. By the way he's the man who makes the KISS
regards Alan