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View Full Version : How do I actually fill Nitrogen?



nak81783
12-15-2001, 11:02 AM
I am looking into buying a scuba tank and fill station so I can fill my own nitrogen tank. I'm pretty sure I know how to fill the nitrogen tanks. I've been around other people that have them and have watched them do it. I just want to make sure I have everything down right, so I don't damage the scuba or on-gun tanks or catch a valve in the face that blows off for whatever reason.

So anyway, once I get the scuba filled, I mount the fill station. Then, I connect the on-gun tank fill nipple to the quick disconnect of the fillstation. I then, open the scuba valve. Next, I should open the valve on the fill station, paying close attention to the psi gauge on the on-gun tank. Since scuba tanks are generally around 3000psi, the pressure in my on-gun tank should equalize to that pressure. Never-the-less, I should watch the gauges. Once the air stops flowing, I should shut all valves. I finally disconnect the quick disconnect, and I am ready to play some paintball.

I think this is what I'm supposed to do, but could someone with some experience, please tell me if I am correct. I wouldn't want to blow myself up or anything. :D

Thanks,
Nathan

Hexis
12-15-2001, 11:41 AM
You are missing an important step in there. On the fill station there will be a bleed valve. After you shut off the air from the Scuba tank, you need to bleed the pressure that's still in the fill station off. Open the bleed valve slowly, when the hissing stops (should be very short), then disconnect the paintball tank from the fill station.

The other thing is to fill it slowly. filling too fast can cause the tank to heat up, which can shorten the lifespan of the tank itself.

nak81783
12-15-2001, 12:01 PM
Ok, thanks. So the slower the better or basically just don't turn the valve wide open?

Hexis
12-15-2001, 12:06 PM
Yep, you can control how fast it goes with the valve on the SCUBA tank.

nak81783
12-15-2001, 02:50 PM
Thanks a lot for you help.

Nathan

Puddleglum
12-15-2001, 03:15 PM
Hey nak, or Hexis. I'm pretty intersted in filling my own tanks. How much would a 4500 scuba tank cost? Is there such thing? What all would I need to fill my own besides a fill station and SCUBA tank?

nak81783
12-15-2001, 03:33 PM
I'm no expert in the area, but with all the research and shopping around I've done on the net, scuba tanks don't come in the 4500psi range. From what I've read, you need either a special compressor or a booster of some sort to do the 4500psi fills. Both of these are really expensive, in the $1,000's. Hexis has helped me out a lot, and will probably correct me if I'm wrong.

DeepFrz97
12-15-2001, 08:25 PM
Actually you can pick up scuba tanks that are up to 6000 psi, but they do start to get a little pricey at that pressure.

nak81783
12-15-2001, 09:15 PM
Whoops! I guess I was wrong on that one then. That's why I have the little "Junior Member" label under my name. :D

TheBigRaguPB4L
12-15-2001, 10:01 PM
what happens if you don't bleed it? i thought it was bad to have your tank dead empty? wouldn't bleeding it just cause it to empty all the way.

nak81783
12-15-2001, 10:13 PM
"Bleeding" is just emptying the air between the two valves. It doesn't empty your tank. It just frees the air trapped between the valve on the scuba tank and the valve on the fill station. It is very similar to the bleed process with a CO2 fill station. (Again, someone correct me if I'm wrong.)

Nathan

TheBigRaguPB4L
12-15-2001, 10:20 PM
well, when we bleed the co2's at my field, it empties the tank, then you fill the tank when it's totally empty.

nak81783
12-16-2001, 07:25 PM
Your right, you completely empty the tank before filling it. But, once you completely fill the tank, you unscrew the thing that pushes down the pin in the CO2 tank. This makes it so no air can escape your tank. Then, before taking the tank off the fill station, you bleed what is left in the lines between the closed valve on the bulk tank and the closed pin valve on your on-gun CO2 tank. You do this so that the trapped C02 vents where you expect it too and not on your hand. (My friend got pretty bad frostbite or something like it from venting C02. He still has a scar from it.)

Nathan

mrhooie
12-16-2001, 09:00 PM
not bleeding the scuba station after a fill and trying to disconnect the tank will result in a few different things you may not ant to happen.

they iclude, but are not limited to - not being able to release the tank due to the pressure, will blow the o-ring inside the quick disconnect, and may cause your tank damage by you dropping it because of the quick force exerted because the air has to escape.

As far as filling it slowly - another reason is so that the gas doesn't heat up too much. When the tank does finally cool down - you'll find that your gauge will read up to 700psi less (gas, hot, expands = more pressure)