TargetTalk

I was at my local sporting goods store yesterday and noticed that they now have tanks rated at 3442 PSI.
Would it be safe to use one of these tanks to fill the Steyr cylinders if I bleed down the SCUBA tank pressure to about 3200 PSI before I use this tank to fill the pistol cylinders.
I was hoping that this would give me more fills before the tank pressure gets low. With my current 3000 PSI tank the pressure drops after a small number of fills. I was thinking that I would fill the pistol cylinder to about 3200 PSI and then bleed it down to 3000 before I attach it to the gun.

Alex

upsdoc wrote:I was at my local sporting goods store yesterday and noticed that they now have tanks rated at 3442 PSI.
Would it be safe to use one of these tanks to fill the Steyr cylinders if I bleed down the SCUBA tank pressure to about 3200 PSI before I use this tank to fill the pistol cylinders.
I was hoping that this would give me more fills before the tank pressure gets low. With my current 3000 PSI tank the pressure drops after a small number of fills. I was thinking that I would fill the pistol cylinder to about 3200 PSI and then bleed it down to 3000 before I attach it to the gun.

Alex

I am not sure what you are trying to do? Doesn't your cylinder have a gauge? If it does just watch the gauge to fill it up to it's max level. Your just wasting air by bleeding the airgun cylinder.

You can hook up your CA cylinder to the scuba tank, SLOWLY open the valve and stop when the pressure gauge on you CA cylinder is at the 200 BAR. You must do this slowly because it will build up heat and you don't want to overshoots the max pressure.

Yes it can. I fear though that people are asking question that indicate they are unfamiliar with the use and hazards of compressed gas cylinders. If that is the case follow exactly what the instructions say, failure to do so and understand working with compressed gas can lead to your or someone else's serious injury or death. This is not the stuff to screw around with and experiment.

I did a (very) quick look-see on the web and it looks like you may be talking about a steel tank that holds 100-150 cu ft of air vs. an aluminum tank which holds about 80 cu ft. The steel tanks are a lot heavier which works for divers, since they don't go to positive buoyancy, but it's just more dead weigh on dry land and they are significantly more expensive. I'm not sure there is much to be gained, especially since a moment of inattention on your part when filling your gun's cylinder may result in an extremely unsafe situation (read: explosion).

If you've got the bread to burn, why not just buy a second aluminum tank? Or, as some on this forum have suggested, buy a Hill pump and use that to top off your cylinders after filling from a tank.

Roger

Greetings,

When I bought my SCUBA tank I was outfitted with a 100 Cu Ft tank which can be filled to 3300 PSI.

I have had it filled twice in the last year with two shooters filling from it.

http://www.airhog.com/tank.htm

Play with the above link to see how many additional fillings you get with a 3300 PSI tank vs a 3000 PSI tank. It is quite interesting.

Cheers,

Dave

Dave:

There is quite a bit of difference - perhaps worthwhile if you shoot a lot even with higher initial capital costs.

So how do you avoid over-filling your gun's cylinder, assuming that it is only rated for 200 bar (2900 psi)? Do you keep an eye on it and stop it manually before it red-lines, or do you just assume that it is within the margin of safety of the cylinder's design? Frankly, both choices make me a tad bit nervous.

Roger

Overfilling a cylinder by 10 - 15% and then bleeding it down is dangerous. You are stressing the cylinder beyond its design. If you want to use a tank that is filled to more than 2900 PSI, then buy a pressure reducer that limits the cylinder pressure to 2900 PSI. Anything else is just unsafe.

I have been researching the SCUBA tanks some more and maybe a safer tank would be one of the 3300 PSI tanks. Since this is only 10% above the normal 3000 PSI, I don't think there is any chance of a cylinder failure.
I tried finding a pressure reducer, but the only ones I could find were from 4500 PSI to 3000 PSI and the cost is between $300 and $400.

[quote="upsdoc"]Since this is only 10% above the normal 3000 PSI, I don't think there is any chance of a cylinder failure.


Gosh that sure does give me a warm and fuzzy feeling knowing you could be squadded next to me with a cylinder continuously overfilled and overstressed. Please think about the benefit v. the risk before going further.

Sounds like it may be a bad idea to go over by even 10%. I'll stick with my 3000 PSI tank since I can't justify the cost of a pressure reducer.

When you bring the tank in to be filled, you can specify to what pressure. If they've filled it to max., just have them bleed it off to what you're comfortable with, before leaving the store. Safer than taking care not to overfill the pistol tank until the SCUBA tank pressure drops.

Paul