Large Booster (ag30,ag15/30 etc) vs Coltri mch6 3.5G omnibooster

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Reku

Contributor
Messages
878
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331
Location
Great Lakes + Northern Florida + Marsh Harbor
# of dives
5000 - ∞
My previous 2.7cfm compressor is dead with no chance of spare parts. It was about 50+ years old. It was dying before I got it. It served me well for a year.

I'm thinking about picking up an mch6 gas powered unit because it has spare parts available and electrical service here is questionable. It helps that it's currently on sale for $2500. Also the coltri compressors are rated for helium, 40% nitrox and other technical gases without voiding the warranty according to the manual.

The sole purpose will be to economically scavenge helium to 0 psi from industrial bottles and leftover trimix from various other tanks. I have so many tanks that are partially full I will break even immediately on compressor cost. However I don't want to kill the compressor. I've read about the care requirements for coltri compressors and the submerged 4th stage in the mch6.

I know the mch6 can't handle banks - I won't be scavenging for longer than it takes to fill a 130 or until the compressor needs a break and then rinse repeat.

I've looked into AG30s / AG15/30s and AG75s for this but the cost and drive gas required are immense. As far as drive gas is concerned I'm currently boosting o2 with an HII 3G-SS-20-O and it works great for the single task it has - I don't need to empty the o2 bottles as o2 is extremely cheap for me. Also as stated above electrical is an issue so having a large enough LP compressor for anything more than a mini booster is problematic...

I am concerned about gas fumes from a gas powered compressor even outside - has anyone ever put an extended remote exhaust onto a honda 160 5.5hp motor before? Assuming the seal on the omnibooster is tight I shouldn't have an issue with fumes contaminating the fills but you can never be too careful. A fume extractor is also an option. I test for contaminated gas every time I fill regardless of type of compressor.

Other unit suggestions would work as well - I just saw that it was on sale, the warranty allows for what I want and thought I may as well look into it.

Other solutions to my issue are also acceptable.

Considering the sale costs of the mch6 vs other options - I feel like I should just jump on this while it lasts.

Thoughts?
 
As the inventer of the Omnibooster, naturally I'm biased and would say go for it. Eventually you'll also need access to a booster for HP O2. My thoughts on a HP booster for O2 are running towards an electric Masterline for @8.5K. Getting a big old 100cfm LP compressor with decent filtration and a Haskel AG15/30, installing the electrical wiring and the pipeing, upgrading the Haskel checkvalves etc wouldn't end up being much cheaper for me.

Michael
 
As the inventer of the Omnibooster, naturally I'm biased and would say go for it. Eventually you'll also need access to a booster for HP O2. My thoughts on a HP booster for O2 are running towards an electric Masterline for @8.5K. Getting a big old 100cfm LP compressor with decent filtration and a Haskel AG15/30, installing the electrical wiring and the pipeing, upgrading the Haskel checkvalves etc wouldn't end up being much cheaper for me.

Michael

I may have to rethink this gas engine idea - apparently I need to keep sound down to 63db at the property line. With the compressor running at 80db-83db and neighbors being about 20-30ft away that doesn't leave much to get the sound levels down.

Has anyone had issues with neighbors and compressor noise?


Regarding hp o2:

At the moment instead of bringing 3000+ psi of o2 I just bring whatever I can transfill and boost a bit more into an 80....which is ends up being around 60cf. If I need more I just bring another 80 with as much o2 as I can get into it.

I'm running lp14s on my CCRs and it's working well.

For now having half full tanks is working fine and I don't mind the extra tanks.
 
@Reku
replacing mechanical fan with electric will reduce noise
replacing the intake filter with a larger one like one from Solberg designed to help silence compressors will help as well
replacing the intake filter and exhaust muffler on the motor will help *though make it bigger and less portable*

You could also get an electric motor and run a generator to power it. More expensive, but generators are typically much quieter and you can separate them.
 
I have an AG30. If you are trying to scavenge every last molecule of Helium, you want a different booster.
 
Just a quick note on that MCH6.. The $2500 one is a standard gasoline model. We bought too many and still have quite a few waiting to be sold. Normally, that wouldn't be a problem but the gas engine has changed on the 2020 units. Electric and 2020 gas units are still on sale for $2700 base price
 
Just a quick note on that MCH6.. The $2500 one is a standard gasoline model. We bought too many and still have quite a few waiting to be sold. Normally, that wouldn't be a problem but the gas engine has changed on the 2020 units. Electric and 2020 gas units are still on sale for $2700 base price

Is the difference in engine large enough in that I should buy a 2020 model?
 
Basically cosmetic change in the Honda line.
 
Basically cosmetic change in the Honda line.
I could be wrong, but it's more than cosmetic. They swapped the Honda GX for a Honda GP. Commercial duty for light duty.
 
https://www.shearwater.com/products/teric/

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