On Board Air from CO2 Tanks

[HeliSniper]

So I've started reading up on what the best solution would be for On Board Air. There is a lot of information on the topic but most of if seems to be conflicting the more you read. So, I started my own proof of concept in a slightly slanted way. It seems to be very clear and undisputed that CO2 is the fastest way to "air-up" after "airing-down", but the Nay Sayers claim that the regulator will freeze up, not enough continuous volume to run power tools, price price price, who can (would want to) afford $800 for a Power Tank, etc...
Instead of throwing money at all the options for On Board Air I thought I would see if I could make CO2 a cost effective viable air source.

I found five 20 pounds CO2 tanks on Craigs List for $20 a piece, so the project begins...



They looked like crap but with a little soap and water, some elbow grease, an angle grinder with a polishing wheel, they started to looking a little better.

 

[HeliSniper]

Project "Got Gas" was in full swing. I was encouraged so far by the progress.
I started looking for regulators that I thought would work. First stop; the welding store. I was stared at with a blank stare so many times that I was almost ashamed to explain it to the next guy, and there was always a next guy. One older gentleman gave me hope sending me to one of the suburbs to a reconditioning shop for regulators. I walked in, looked around and thought this is the place. If anyone can help these people can, five minutes later I was surrounded by 4 guys all with blank stares telling there's no freekin way that will work. One guy told me that if I put CO2 in a tire and as the tire heats up from normal driving, the tire will blow up because the gas will continue to expand. Now I am by no means an expert no am I a scientist but I am a Master Diver and I did spend the sleepless nights having Boyle's Laws of Gas pounded into my head (some of it actually stuck) and have had to, on many occasions, mix my own Tri-Mix gas for diving. With that said I knew the guy was full of crap but was still faced with the fact that I needed a regulator that would not freeze yet give enough volume of flow to run air tools and quickly air up big tires many many times. So I just started looking for CO2 regulators and figured that if they failed that I would try to modify them to suite my needs. First one that caught my eye was one from the new Edge Series made by Victor. I knew this had a great gauge since all we used while I was Iron-working and High-raise Welding was Victor gauges and they never once failed. I was told this gauge would cost me close to $800 and I knew right away that this would not be the gauge for me. The next, another Victor gauge but this one had fins for heat sinks, and I thought this would be perfect, there is no way this thing is going to freeze up. I was told that yes this gauge was in fact a high flow CO2 gauge that was made not to freeze and it would cost me in the neighborhood of $1,200. Yep, wrong neighborhood. So after many Google searches and scavenging around I found on Amazon a CO2 regulator with a fixed PSI setting of 150psi that was only about $40, yep, this is my neighborhood, so I ordered four. My thinking here was 150psi would be what I need to quickly fill the tires but I would still need an in-line regulator to bring the pressure down to about 100psi to run power tools. I found one on Amazon for $30, so I got two. As I was waiting on my Amazon stash to arrive I continued looking and scavenging for other regulators in the event the $40 ones did not work. Low and behold on eBay I found my Victor Edge Series CO2 Regulator used and for $200 or best offer, it arrived at my loft for $100 and I was happy. As I continued my search I also found some of the Victor $1,200 heat sink looking regulators on eBay for $600, so in normal fashion I offered $100 for 2 of them delivered to my loft. Before I could shut down my computer I was informed I was the proud owner of 2 slightly used Victor Heat Sink High Flow CO2 Regulators and they would arrive early next week. That was a good day. So here are some pictures of my menagerie of regulators.....

This is the Fixed 150PSI Regulator with a stainless steel ball valve:



This is the Victor Edge Series ......


This is the Victor High Flow Heat Sink Regulator......



and this is the in-line regulator to bring the psi down to about 100psi to run air tools.....

 

[4xFar Adventures]

I've had a CO2 setup for about 4 years now and have never had an issue with the regulator freezing. It will get a layer of frost on the outside of the regulator, but the internals remain unfrozen. There are no gauges because the tank will read full pressure until it's empty. You can have one to read the tire pressure though. The only way to know how much CO2 is in the tank is by weighing it. I believe the regulator on it is 150 PSI.

If you want to keep your polished tank, you'll have to find a shop that will do so. Most are done on an exchange basis. Like a propane tank, the CO2 tank will have an expiration date. The advantage of exchanging them is that you don't have to worry about the expiration date as long as you turn it in before the date stamped on the tank. I don't know what the initial buy in is if you don't have a tank to start with, but I get a full 20# tank swapped for $25 at Airgas.

 

[HeliSniper]

Disco, thank you for the picture and your message.

4 years now and have never had an issue with the regulator freezing. -

That's what I suspected because there should be no water vapor inside the regulator.

There are no gauges because the tank will read full pressure until it's empty - Yes, it cracks me up seeing a high side gauge on a CO2 regulator (even Power Tank).

This is why my next entry will be about Portable Scales. I have been playing with Luggage Scales and Deep Sea Fishing Scales. Both seem to work equally well now it's down to cost and ergonomics.

If you want to keep your polished tank, you'll have to find a shop that will do so -

Yep, already discussed this with many welding shops, most just require that I leave it there over their CO2 fill day or bring it and wait on their CO2 fill day. Some said they will fill it while wait with no qualifications. I am working on a deal now that I can get a large CO2 tank delivered to my hangar with my Oxygen and Acetylene and just have my own CO2 fill station there. I just have to take them in to Hydro-ed and Visually Inspected for my own safety and to comply with state and interstate laws for transporting compressed gasses.

Great information - Thank you for your insight and pictures!!

 

[adventure_is_necessary]

I was recently gifted a CO2 tank and regulator. This was something picked up at a Harbor Freight or an equivalent. I had some reservations about using it, but it appears it'll be a good tool. I've used CO2 cartridges on bike tires before and rarely had issues with them. Now, my tank is nowhere as large as what you're using, as it's something similar to a paintball tank, but it'll do what I need it to do.

 

[old_man]

My local Airgas will not refill a polished tank or a painted tank. They coat the tanks with a temp sensing paint. If you heat up aluminum, you modify the temper and the strength. Powder coat temps are a concern . I own my tanks, not lease. I have wanted to powder coat mine (I have a powder coat setup and can do it with low temp powder) but if I do, I will have to have it recertified.

 

[HeliSniper]

My local Airgas will not refill a polished tank or a painted tank. They coat the tanks with a temp sensing paint. If you heat up aluminum, you modify the temper and the strength. Powder coat temps are a concern . I own my tanks, not lease. I have wanted to powder coat mine (I have a powder coat setup and can do it with low temp powder) but if I do, I will have to have it recertified.

Good point Old Man. Every tank I acquire I get re-certified even if it is still in date. I don't know what the guy before me did with the tank so I will not endanger anyone for the few dollars it takes to get certified.

 

[Guerrero]

My local Airgas will not refill a polished tank or a painted tank. They coat the tanks with a temp sensing paint. If you heat up aluminum, you modify the temper and the strength. Powder coat temps are a concern . I own my tanks, not lease. I have wanted to powder coat mine (I have a powder coat setup and can do it with low temp powder) but if I do, I will have to have it recertified.

Wow, that blows, I have painted tanks and they take them with no problem, the only downside is I have to wait a few days for fill and return.

 

[old_man]

I called General Air and they will refill a painted tank. They are also less than half the cost of Airgas.

 

[Anchor Mtn]

I use that same 150psi regulator on my CO2 tanks.... never had a problem with it. Its small, simple and cheap!

 

[old_man]

I had nothing but grief with the adjustable regulators freezing. I went with a cheap fixed pressure regulator and have had no problems since.

 

[HeliSniper]

I had nothing but grief with the adjustable regulators freezing. I went with a cheap fixed pressure regulator and have had no problems since.

That right there is great information and good news!!

 

[HeliSniper]

I called General Air and they will refill a painted tank. They are also less than half the cost of Airgas.

I believe there is some leeway for CO2 in that it is not a HIGH pressure fill. Air, O2, and other gases can go as high as 3,000psi whereas CO2 remains about 850psi as the liquid in the tank gets additional room and pressure relief from the expelling gas and converts additional liquid to gas in the tank, until empty. This is why you cannot use tank pressure, you have to weigh the tank to determine remaining (gas) volume.
So I believe some places understand this and, while still using reasonable caution, will fill painted/modified tanks. Whereas others, like AirGas, will just issue a blanket rule for their employees to follow so there is no confusion and thus no catastrophic event. Just my thoughts......

 

[Kent R]

I got a fixed HyperFlo regulator from Wheelers Of-Road in Grants Pass OR, I have never had any problems with it.

 

[HeliSniper]

Update: I have polished a couple of tanks now and each one has passed the Hydro testing and have new dates.

 

[HeliSniper]

Now I'm just exploring options... like pretty red valve knobs....

 

[Funmobile]

I went with an SCBA tank, and a spare O2 regulator from an extra oxy / acetylene setup I have. All i needed to do was swap the standard regulator inlet fitting for a CGA-347 fitting. Then I swapped the 1/4" np male/male nipple where the O2 hose mounts, for a female air QD with male threads. It is extremely light and works great.

 

[peeeeetey]

If you want air tools better to run nitrogen. Different tanks different everything. CO2 is more reactive to temperature so your tires will fluxuate in pressure as the outside temperature increases and decreases. Also none of those tank ice ups.

 

[HeliSniper]

If you want air tools better to run nitrogen. Different tanks different everything. CO2 is more reactive to temperature so your tires will fluxuate in pressure as the outside temperature increases and decreases. Also none of those tank ice ups.

How much fluctuation is there between Nitrogen, Air, and CO2 if you were to inflate a tire with each? Also, how many cubic feet of Air, Nitrogen or CO2 can you get in the same size tank?