If that's the case, There are compelling reasons to abandon that thought. Expense and filtration concerns being at the top of the list. Booster pumps, like the Haskels, are designed to boost lower pressure gas, like an O2 or He tank (that are only about 2200# new) to typical scuba tank pressures. These booster pumps run on 125# air supply. (like from a workshop compressor) Note that they are compressing an already pure gas, so filtration isn't an issue.O2 cleaning and service is another matter if working with O2. A haskel takes some time to fill a scuba tank depending on the supply gas pressure and volume to be put into the tank. It does all this for the sum of about $3500. (Not counting filtration, if you want to boost shop air) You can go buy a small brand new compressor Designed For filling scuba tanks, with filtration and all, ready to use for just slightly more, or a used one for considerably less.
Anyway, just the thoughts of a dottering old lady who spends too much time in the hot sun.
Darlene