Size of air tanks question
HI, I’m trying to decide on which size air tank to get. I’ve kind of ruled out the 4500 psi tanks, even though I would like one because they are so small, mainly due to the fact that I can’t find anyone around here that can fill one to that psi.
I would like to have one at least small enough that I could carry it in a backpack. I called a scuba shop and they said they sell them in 30 cubic feet, 40, 50 etc as well as the 50 pound 80 cubic feet tank.
My question is, about how many fills could I get from say, a 30cf tank if I have a .25 caliber condor? Thanks
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If you set your gun up to shoot at lower PSI say 2,500 or 2,300psi you’ll get A LOT more fills to the psi your tuned to…great idea in my book as my gun gets REALLY consistant after psi drops down a bit from 3,000 psi. I am going to setup a 1,000cc tank at 2,200psi and it is going to be just crazy # of consistant shots. I need to post my latest charts but I’m getting over 140 insanely consistant shots in the 650fps range seriously out of a 200 shot string the last 140 are damned near a straight line!
Jim.
Ooooo….that sounds fantastic. Details please 😀
Yup those are called “Pony Bottles” and AirHog sells them maybe others?
If you set your gun up to shoot at lower PSI say 2,500 or 2,300psi you’ll get A LOT more fills to the psi your tuned to…great idea in my book as my gun gets REALLY consistant after psi drops down a bit from 3,000 psi. I am going to setup a 1,000cc tank at 2,200psi and it is going to be just crazy # of consistant shots. I need to post my latest charts but I’m getting over 140 insanely consistant shots in the 650fps range seriously out of a 200 shot string the last 140 are damned near a straight line!
Jim.
Thanks so much for that link… those are pretty good deals.
Anyone have any other links to some small 4500 tanks?
What about these tanks? Would they work?
http://badboyztoyz.com/store/cats/airsystems/purenergy.htm
http://www.pntball.com/Items/83560790
Also, I’ve read that the condor is actually around 2700psi so wouldn’t a regular scuba tank be ok then?
Thanks so much for that link… those are pretty good deals.
Anyone have any other links to some small 4500 tanks?
David, They hydro tanks with water in the tank, I think. less energy released if a tank should rupture.
I could rent a 400 cf cylinder of nitrogen at 6000 psi, but I would need to buy a regulator for 2 or 3 hundred$$, and you would not want to move it much!
I need to talk to someone in the fire dept. I bet they have compressors to fill there Scottpacs. The HFD fire school is not far from me. I need someone on the inside.
This started out as a damned funny post as I read it 😆 thanks for the laughs…
Given your mobility requirements I’d get a pump and if you have a few extra bucks at least an 80cubic foot 3,000psi tank…if you find a place to refill to 4,500 get with Joe’s air tanks and get a Carbon 4,500psi one which is easily packed around. The SCUBA is car portable and is a nice break from the pump 😆
http://www.hamcontact.com/airgun/HoseAssembly/
Let us know what you come up with.
Jim.
Another possible source for 4500 psi fills is the company that hyros your local fire departments SCBA tanks.
You could also maybe do what I do, rent a high pressure industrial cylinder. My local gas supplier keeps 4500 psi, 443 cf nitrogen cylinders in stock. I usually fill to 3000 psi, refill at 2000, that gets me more than 150 fills. At 40 to 60 shots per fill, that’s a shit pot full of pellets! Gas costs me $60 or so, tank rent is another $10 a month. Rented my first tank last August, just ran it below 3000 psi 2 weeks ago. That’s a LOT of shooting for only $20 a month, and no pumping! I use nitrogen just because that’s what they keep in stock, they could get compressed air, but it would be a special order. Good luck!
Dave
Pressure can increase or decrease with temperature.
What are you referring to, straight numbers, other stuff, gases (gases)?
For our purposes temperature of the gasses will make things appear different. The temp will change due to fill rates, discharge and compression of gases, tank temps.
Temp goes up pressure goes up, and likewise if the temp drops, so does the pressure, you still have the same amount of gas in the cylinder.
With us only using air it eliminates some of the variables of mixing dissimilar gases.
one more question, does the pressure of a scuba tank (and the air gun for that matter) decrease over time if you don’t use it, like if I didn’t shoot the gun for a month? Thanks
Only if it is leaking, and it shouldn’t be leaking.
rustykfd you said, “These are just the straight numbers, other stuff comes into play with compressed gasses, but this should illustrate the differences.”
What are you referring to, straight numbers, other stuff, gases (gasses)?
Thanks guys.
one more question, does the pressure of a scuba tank (and the air gun for that matter) decrease over time if you don’t use it, like if I didn’t shoot the gun for a month? Thanks
Keep in mind that some tank sizes are stated in Liquid Capacity (cc, liter) and some in Gas Capacity (cf)
Gas is compressible, liquid is not.
A 490cc tank is .49 liter (these are liquid volume) and .073cf at atmospheric pressure and 3.5 cf at 3000psi (gas volume)
Say you use 1/2 of your 490cc tank and refill with an 80cf SCUBA tank it will take 1.75cf from your 80cf tank. If your 80 cf tank started at 3000psi it will now be 2943.
These are just the straight numbers, other stuff comes into play with compressed gases, but this should illustrate the differences.
Did I do my math right??
Make sure you are comparing apples to apples.
Rusty
Just for the record, a simple web search will show that 1 cc = 0.0000353 cubic foot.
A link that may interest you is http://www.airhog.com/tank.htm
If you need something of more detail, like what is Charles’s law, etc. send me an email, that is more than most would want me to discuss on the forum.
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Well after looking more closely I realized they are rated in cubic “inches” not feet 🙁
Jim.
But won’t that be less powerful?