TargetTalk

I just purchased a used Anschutz 2002CA rifle with a scuba tank.

The previous owner said she only filled the compressed air (CA) tube 'about' a dozen or so times.

3 questions:

1. upon attaching the CA tube to the scuba tank, how long should I leave the scuba tank valve open? (the CA tube seems to heat up a little)
2. how can I check the volume in the scuba tank?
3. assuming the previous owner filled the CA tube only about a dozen times, how many refills can I get out of the scuba tank?

This seems to be a full sized scuba tank, it stands approx 30" tall

1. upon attaching the CA tube to the scuba tank, how long should I leave the scuba tank valve open? (the CA tube seems to heat up a little)

Unless you're in a hurry, leave the valve open until the temperatures have equalized. You'll get a better fill that way.

2. how can I check the volume in the scuba tank?

You'll need a yoke with a gauge.

Richard

I don't leave the cylinder on for the temperatures to equalize. I don't have the patience to stand and wait for that and even though my scuba tank is chained to the wall I don't like to leave the tank with the cylinder attached. I just fill the 2002 cylinder slowly. Also, if you fill it frequently and don't wait for the pressure to drop too low then less heat will be generated when you fill.

You really can't exactly tell how much volume is left in the scuba tank only how much pressure. The most common tank size and a good one is an 80cu ft aluminum these days. These are typically 3000 psi tanks. The pressure rating will be stamped into the top of the tank. To figure out the size of the tank measure yours and knowing the pressure rating poke around the net a bit and you should be able to get the size of the various scuba tanks that are out there and figure out what you have from that.

My alu 80 fills my rifle and my daughter's air rifles for almost a year. Can't exactly say how many fills that is.

We use 3 Alu 80's at our club, we take the one that is partially full and use it for the really empty tanks, then a full one is used to top them off. The third tank is kept as a spare.

We shoot 3 nights a week, up to 7 kids at a time, (maybe 1/2 to 1/3 shooting 888's which are CO2) I take a tank to be filled about once a month.

I use the gauges on the rifles, when they aren't gettting close to full anymore we move the top off tank to be the first tank, pull out the full spare, and I get the one that was the "use first" tank filled. From what the dive shop guys say the tanks are only down to 1500 PSI or so when I bring them in to be filled. They can't figure out why we don't empty them.

The 2002CA's and the 9003's seem to fill slower than the P70 Jr's do. If you crack the valve open with a P70 Jr cylinder attached their needle just jumps up to the new level (their cylinders also seem to get hotter whcih makes sense). The 2002's needle goes up slowly. But it only takes them 15-20 seconds to fill up, less time if they are not completely empty.

The cylinder gets hot when you fill it because you are increasing the pressure in the cylinder. You may notice that the scuba tank or the tank valve gets cool. That is because you are reducing the pressure in the tank.

You want to just crack the valve on the scuba tank and fill the cylinder slowly. That way the cylinder will not heat up as much and you will get a better fill. I take about 3 or 4 minutes to fill my cylinder. When I do this it only warms up slightly.

I just keep on refilling the cylinder untill the the tank will not get the tank gauge to the top of the green.