Teach me about boosters - ScubaBoard

get a baby booster, which one is up to you but doesn't really matter which one you get, they're all equally inefficient for what they are. Used is fine, but if it needs rebuild, budget about $400 for the parts from Haskel. They do have service videos on youtube, they're stupid easy to rebuild.

I would recommend spending a bit of money filtering the shop compressor. Clean though you may think, your booster will appreciate cleaning and it needs to be filtered to 5um or so per the manufacturer.
I got one of these for my AG30 which spits out Grade D air which is more than clean enough for boosters. Only difference between it and scuba "grade e" air is the conversion of co to co2 which the booster doesn't care about. Costs about $400 and is probably more than overkill, but if it saves at least one rebuild of my AG30 over the life that I have it, it will have paid for itself just in the parts
350 SERIES Modular Clean Air Package 1/4, 3/8, 1/2

After that, there isn't a lot to it. You'll want to keep it cycling less than 1 cycle per second, open valves slowly, etc etc. The manuals out there are pretty good. I was planning on a dryer and I have had good success using motorgaurd filter on the shop air. Painters love them, my plasma torch has always been happy with one in place for the past 15 years. I've always heard of them as a great compressed air filter. My intention is to just use the compressor at home as drive gas. Any breathing air will still come from the dive shop (the local one that doesn't pump O2). I still have plenty of big tanks around.

I wasn't sure if there are any to avoid? Or any that have an outstanding reputation, or crap reputation? I understand that they are not efficient, nor do I really care. I have been watching used ones pop up, but not knowing much about them I tend to back pedal a little not knowing what I am looking for, or what I should be looking for. When they sell right away I guess that was a good one, but I wouldn't know if something that isn't worth rebuilding. @broncobowsher depends on the degree of filtration from the motorguard, but if you have one of those they will certainly help, especially with a drier. I got the clean air package to put in my pelican case so I can use any air source, but if you have this thing permanently mounted then a drier and something like the motorguard should be fine, just make sure the filtration level is low enough to at least meet the factory recommendation for the booster you purchase.

that's a great deal. Spend about $800 or so on the parts I think since it is 2-stage and O2 clean it and you have the gold standard of O2 boosters on the market for less than half price *New is $7k*. A new baby booster is $, so an extra grand and you get 30:1 instead of 25:1 *really nice for dil bottles since the baby booster dies around psi vs. psi for the 15/30* and a lot more capacity since it's a beast.
Haskel Booster

@broncobowsher depends on the degree of filtration from the motorguard, but if you have one of those they will certainly help, especially with a drier. I got the clean air package to put in my pelican case so I can use any air source, but if you have this thing permanently mounted then a drier and something like the motorguard should be fine, just make sure the filtration level is low enough to at least meet the factory recommendation for the booster you purchase.

that's a great deal. Spend about $800 or so on the parts I think since it is 2-stage and O2 clean it and you have the gold standard of O2 boosters on the market for less than half price *New is $7k*. A new baby booster is $, so an extra grand and you get 30:1 instead of 25:1 *really nice for dil bottles since the baby booster dies around psi vs. psi for the 15/30* and a lot more capacity since it's a beast.
Haskel Booster

I looked at that used one. The assortment of used red shop hose and what looked like a garden valve was not that appealing to me. Looking at that one, then looking at a brand new baby booster at what is the same price, the baby looks like a better deal to me. Add in the $800 rebuild. Not knowing much about them to start with, starting with a good new unit looks better.

I'm not looking to fill to , just 200~232bar. Is there something that the 2-stage offers that would be a huge benefit? I'm not looking to pump up 120s, mostly just 3L rebreather bottles. Maybe top off a bail out a time or two a year.

I get it, pump slow. Open valves slow. Don't be in any hurry. I've only had one accidental Oxygen fire, few more intentional. I've owned oxy-fuel torch set for a very long time.

Everything seems to be centered around a Haskel, anything else I should consider? At the moment a Haskel baby booster is probably the direction I am leaning. For roughly $2k new I wouldn't really have to worry about used issues. And I do realize there will be way too much money tied up in whips and tank adaptors on top of it as well.

I’m getting a little tired of the long drives that I’ve got to make in order to get fills for the 2 liter HP steel cylinders that I use with my CCR. The only local shop that can reliably supply O2 at sufficient pressure now charges much too much for a fill, ($20.00, as opposed to the $7.00 or so that I pay at more distant shops), and they cannot provide trimix fills.


I’ve done a bit of research and am seriously considering purchasing a small booster, either a Hydraulics International Compact Booster, or, more likely, a Haskel Mini Sport MSB- Booster.


For a variety of reasons, I do not wish to purchase a compressor, so must rely on OC cylinders and a regulator to supply drive gas.


I have been unable to find any hard data regarding the volume of drive gas that the Haskel booster requires. I’ll start with supply gas in steel 100’s at 3,500 PSI, and can probably get a couple of transfer fills without having to boost at all, then boost the gas as the supply cylinder pressure decreases.


Can any of you more experienced souls please provide me with an approximation of the volume of drive gas that I can expect to require to run the booster to fill the 2 liter cylinders?

Thank you TrimixToo. You posted a link to that very source recently in a thread started by boulderjohn. I downloaded the file, and opened the Zip and found that the software is only formatted for PCs. I use a Mac and was unable to access the information.

Regarding using a small shop compressor, (which I'd prefer to avoid,) doesn't the Haskel require drive gas to be delivered at a continuous 150 psi and at a reasonable fpm rate? That seems to demand a rather hefty compressor.

A Haskel does not need to be operated at a constant drive gas pressure. Varying the pressure at the pump (via adjustable regulator or valve or both) is how you control cyclic rate and maximum output pressure. For a mini-booster you should not need anything close to the 5HP shop compressor I use for my AG-30. For pumping 02, you will want the cycle rate to be 50/minute *or less* for my booster, and if the drive gas pressure is set to 100 PSI, for example, the maximum O2 pressure would be PSI. The MB probably has different numbers.

I fired up the software, though, and I don't see the mini-booster in it. You could call Haskel or Nuvair to ask about drive gas requirements, or find a PC (yeah, I know) and calculate what you need from a similar but larger booster's numbers.

For my AG-30, it's impractical to use stored drive air to do anything much. The drive gas requirements are just too high for blending into large doubles and LP72 deco tanks. For a RB, it might be reasonable, but you will need a fairly expensive adjustable HP regulator that might well cost more than a small shop compressor, and you will need air fills to do anything at all. You might look into using T bottles of N2 as drive gas instead, which might cost less, if you are really opposed to a shop compressor. Thank you RayfromTX, and thank you once again TrimixToo for your courteous, insightful and informative response. Thank you as well for opening the files that I could not access on my Mac. I am truly appreciative of your going the extra mile to assist a compatriot who also happens to be a total stranger.

My next step may well be to contact the folks at Haskel or Nuvair. (I have a friend who used to work for Nuvair, but he left that position several years ago.)

There are several reasons why I’d prefer not to have a compressor. The only place where I could put and use it would be in our garage, and my wife has this inexplicable desire to occasionally put her car inside, especially when she returns home during one of our frequent torrential rain storms. Who could have imagined that?

Most of the units that have the capacity to run the Haskel are very loud. I’ll be doing fills well into the night and have no desire to disrupt the neighborhood with noise pollution. Things are bad enough around here with the infernal whine and bellowing of the local leaf blowers, barking dogs, ambulance sirens, and heliport.

Our garage’s wiring may not be able to support the amperage that a suitable compressor requires. Putting a 15 amp load on an already busy 120 circuit may not be tenable. We’ve got a 220 line which we use for our clothes dryer, but any compressor that runs off of 220 will most likely be very loud and probably be overkill for its’ intended purpose.

A compressor is yet another bit of equipment that will require my attention and maintenance. I’ve owned one in the past, and this is not a major obstacle, but one that I’d prefer to avoid. A preliminary search yielded a pair of compressors that may suit my needs, but I’ve never actually seen either of them, an Eagle EA-, and Campbell Hausfeld DC both seem to be quiet enough for my domestic situation, and pull low enough amperage to suit the available circuit. I do not know however if they have the capacity to efficiently run the booster.

I’ve got well over a dozen SCUBA cylinders, a pair of which I’d use for supply O2, and another pair for trimix dil; leaving me with plenty to use for my OC dives, air dil, and drive gas. Getting good, affordable, fast EANx and air fills locally is not an issue, just O2 and mix, for which I’ll have to drive and wait a few hours when necessary. I can deal with that a couple of times a month. I’ve also got several reliable regulators, one of which I can designate for use of the drive gas supply. I can't give you hard data, only anecdotes. I have a mini HI booster, I can dig up the exact reference, but it's the one sold by Add Helium (I'm a dealer too). When filling 2 or 3 liter steels from a full O2 cylinder, it takes a couple of hundred PSI out of your steel hundred. When filling your 3 liter from a nearly empty O2 bottle (getting the last 100 PSI from 400 to 300), it takes nearly the whole steel 100.

My friends in Hawaii have the Haskel version of that booster. They drive it with a home depot 2 HP shop air compressor (the rigid with the 40 gallon tank) at 240 volts (they unplug the dryer and plug in the air compressor) with no issues at all.

Your question is how much air does it take. The answer is "it depends on how much pressure you start with". That's the best I can do for you. If you dive semi-regularly, you will save money buying a shop compressor over getting your hundreds filled. It’s going to be interesting to see just how many posts folk can do before someone answers the OP question properly.
Either that or this has to be the hardest question in the world of diving to ask.

“How much drive air does it take to run a Haskel Mini Sport” over the full range of supply oxygen pressures.

Would have thought we would have the answer by now, after all the companies selling them have been doing it for years.
That, or its so darn much no one dare give you a straight answer for fear knowing at $2 a tank for drive air it costs more than the $7.00 oxygen fill.

Who would have thought a drive air chart would be such hard work to get hold of.
Hope we get there by around post 30 which is just about the same CFM rate you need to drive the thing full range in the first place.