Haskel Mini Sport for filling AL40 / AL80 Deco Cylinders?

[Jack Hammer]

@mdwalter and @lermontov
Thanks for your input. To clarify, am looking for real world experice specifically with the Haskel Mini Sport booster and time it would take for creating simple EAN or 100% O2 deco gasses.

Let's use a hypothetical scenario. I have an empty AL40 want to create an EAN80 mix. I have a partially used industrial cylinder of O2, and after equalizing that into the AL40, I have roughly 850 PSI of oxygen in the AL40. To make the EAN80 mix, I now need to boost roughtly another 1370 PSI of O2 before topping with Air to 3000 PSI.

Assuming a steady supply of 150 PSI boost gas from HP scuba tanks with a regulator attached, the question I was hoping to answer is how much time and boost gas would a Haskel Mini Sport require to boost that additional 1370 PSI of O2 (to get from 850 to 2220 PSI O2) into an AL40?

From @broncobowsher experience, it sounds like quite a bit of time and gas; though I'm not sure if he was filling 80s or 40s.

I have a Haskel mini and have been using it regularly for a few years. As mentioned, the lower the supply gas and the bigger the difference to your target fill pressure the more drive gas will be needed. So in short, it's gonna take a LOT of drive gas and take a LONG time to mix that 80% from an O2 bottle with only 850psi to start. Comparatively, I'd guess you would use about 1/8 the drive gas and time if your supply bottle was closer to 1500psi.

I fill top off my rebreather O2 bottle from an al80 down til about 1400psi before refilling the 80. Much lower and it becomes very time consuming to fill my 3L. Also IME the mini becomes almost useless once the difference in pressures between the supply bottle and the bottle being filled gets to be more than about 1,800psi.