usable air ?

[beerthief]

something i have never seen is how much usable pressure is in a scuba type tank ? 50% ? 73% 89% what ? i have seen something like this will fill your 300cc tank to 200 bar 26 times but what percentage of the tank is used ? just wondering is all
Thanks

 

[Trucker3573]

No idea what percent it uses each fill. There is a calculator on airguns of Arizona website that estimates fills you will get. I guess you could guesstimate the percent used each fill from the number of fills you would get.

 

[beerthief]

ok thanks

 

[ctshooter]

Well compressed air is compressed air, right? Let's do this with simple math numbers.

You have a 10L tank at 300 bar. You fill your gun say 100 times and it's down to 200 bar.
Well 10L compressed 300 times is 3,000 liters of sea level pressure air, correct so far?
Now you end up with a tank filled with 10 L of 200 bar air which equals 2,000 liters of air at sea level.
So you used up 1,000 liters of sea level air which is 33.33%.

The math is pretty easy if you use bar. You used up 30 bar of a 300 bar tank - well that's 10%.

The question is what percentage of 'usable' air have you used up. Let's say you refill your airgun at 150 bar. If you keep refilling your airtank from a 300 bar tank until it will no longer fill the gun when it is down to 150 bar - you have used 100% of the usable air in the tank.

Now let's take a more realistic approach. Let's say I have an airgun with a reg set at 150 bar. I fill that airgun to 250 bar each time it hits 150. Now the tank I use is a big 300 bar tank and I use it to fill the tank until it gets down to 250 bar and can no longer fill my gun to 250 bar. At this point I have used only 33.33% of the 'usable' air in the 300 bar tank. 50 / (300 - 150) = 33.33%

 

[beerthief]

Well compressed air is compressed air, right? Let's do this with simple math numbers.

You have a 10L tank at 300 bar. You fill your gun say 100 times and it's down to 200 bar.
Well 10L compressed 300 times is 3,000 liters of sea level pressure air, correct so far?
Now you end up with a tank filled with 10 L of 200 bar air which equals 2,000 liters of air at sea level.
So you used up 1,000 liters of sea level air which is 33.33%.

The math is pretty easy if you use bar. You used up 30 bar of a 300 bar tank - well that's 10%.

The question is what percentage of 'usable' air have you used up. Let's say you refill your airgun at 150 bar. If you keep refilling your airtank from a 300 bar tank until it will no longer fill the gun when it is down to 150 bar - you have used 100% of the usable air in the tank.

Now let's take a more realistic approach. Let's say I have an airgun with a reg set at 150 bar. I fill that airgun to 250 bar each time it hits 150. Now the tank I use is a big 300 bar tank and I use it to fill the tank until it gets down to 250 bar and can no longer fill my gun to 250 bar. At this point I have used only 33.33% of the 'usable' air in the 300 bar tank. 50 / (300 - 150) = 33.33%

Thankyou very much that sounds like the answer i was searching for ,

 

[Scotty1]

That made my brain hurt for some reason.

 

[steve-l]

If you read between the lines, there is little advantage in using tank pressures over 250 bar. Airguns start loosing accuracy when pellet speeds start to exceed 900 ft/sec. To achieve the most consistent and accurate tunes regulator pressures will range between 100 and 140 bar. In my experience using larger storage tanks at lower pressure will deliver more gun recharges than using smaller tanks at higher pressures with a whole lot less stress for all your equipment.

 

[Airgunmann]

If you use a regulator it puts more pressure on your regulator and your speed fps should stay the same no matter if there is 250 or 175 bar your fps should stay fairly steady that is the point of the regulator most of your guns were set up to 200 bar or about 3000 psi and the larger tanks that you fill to 4500 psi are only thing that can fill them to the full amount unless your just using 2800psi or lower and they are usually not regulated the newer 250 some 300 bar stuff are using regulators set like stated 100 to 150 bar output to keep the speed of pellets down but with all the slug hype you need higher pressure and or longer barrels because they like the higher speed and we or some people are finding some of the heavier pellets do well up to 930 fps not all of them though kind of just depends on the barrel , twist rates and other factors but I understand what u are saying also with larger tanks and not filling as high