I have an A-5 w/ E-grip, JCS gold powertube, palmer stabilizer set at 490 psi and 20 oz CO2 tanks w/ anti-siphon tubes. I get 285-290 fps.

With a filled CO2 tank, the pressure on my reg. will creep up when not firing to 600 psi and make my gun fire hot. With sustained fire, the psi will stay at 490. Only when my tanks are emptied to 14-15oz will my gun stay at 490 psi, and give me a standard deviation of 5-6 fps.

I know that a 20oz tank with 20oz of CO2 has a much higher pressure than one with 15oz, but shouldn't my stabilizer regulate or keep the output pressure at the correct setting even when the input pressure is fluctuating? Is there something wrong with my stabilizer or is the pressure creeping up with a full tank when the gun is not firing normal?

ken17golf wrote: I have an A-5 w/ E-grip, JCS gold powertube, palmer stabilizer set at 490 psi and 20 oz CO2 tanks w/ anti-siphon tubes. I get 285-290 fps. With a filled CO2 tank, the pressure on my reg. will creep up when not firing to 600 psi and make my gun fire hot. With sustained fire, the psi will stay at 490. Only when my tanks are emptied to 14-15oz will my gun stay at 490 psi, and give me a standard deviation of 5-6 fps. I know that a 20oz tank with 20oz of CO2 has a much higher pressure than one with 15oz, but shouldn't my stabilizer regulate or keep the output pressure at the correct setting even when the input pressure is fluctuating? Is there something wrong with my stabilizer or is the pressure creeping up with a full tank when the gun is not firing normal?

How long have you been using the Stabilizer? With CO2, even with the anti-siphon and regulator, cool gas, as it sits for a while in the chambers after the regulator can warm to ambient and expand greatly...giving you a higher pressure than expected even though the last shot was at your regulated pressure. Sometimes regulators can leak allowing pressures to climb, but when they do internal gun pressure usually climbe to full tank pressure.

Now, pressures in tanks, it makes no difference whether there is 20oz or 15oz in the tank, the pressure is the same...about 800 to 900 psi. The only time when pressure drops is when thee is no liquid left inside to evaporate. As long as there is liquid in the tank the pressure(over liquid) stays about the same.

After the liquid is gone pressures drop for a few dozen shot until bottle pressure drops below you regulator setting. But those shots are well regulated providing very steady velocity.

Dare I suggest it, HPA will eliminate those problems.

I've had the stabilizer for a couple years, but to be honest, there has probably been only 12000 shots with it. Haven't played much... But I think it it broken in. I keep the gun and reg. well oiled.

Bruce...

I have found this chart in a couple places, and supposedly it came from Glenn Palmer. This is the pressure in a 20 oz tank at 72*F with varying CO2 amounts.

21 oz *1150 psi

20 oz * 950 psi

19 oz * 875 psi

17 oz * 825 psi

15 oz * 815 psi

12 oz * 810 psi

6 oz * 805 psi

2 oz * 800 psi

The pressure is pretty consistent, so I still don't really understand why the gauge(output/gun?) pressure on my stabilizer will creep up to 600 psi with 20 oz and stay at 490 with 15oz, unless it is liquid getting in the stabilizer.

With a full tank, when I fire the gauge will be at the set 490psi. If I then let the gun sit, it will slowly go up to 600 and the next time i shoot it will be hot. It is just when I let it sit, it slowly increases...

I know HPA would be great, but I don't play enough to spend much more money on paintball.

daniero wrote: Is there a point in having a regulator and an expansion chamber? I wonder...

Actually, yes. If you have the money. Even though regulators like the Palmer Stabilizer  can handle a shot of liquid CO2 without being damaged, if liquid goes into it it can get to the downstream side. Once past the regulator any liquid will then expand causing a higher pressure spike.

If you installed an expansion chamber before the Stabilizer it would assure much less likelihood of liquid making it into the Stabilizer. Same thing can be said for the remote setup and the siphon tube setup. The object is to get things so the regulator has to deal only with gas.

Thanks for the replies...

I'm going to see if I can contact PPS and see what they say.