TargetTalk

I have two air pistols that are recharged from a 3000 psi scuba air tank. Recently I purchased a Daystate PCP air rifle that requires a 4500 psi air source. My question: is it possible to refill a PCP air pistol cylinder from a 4500 psi tank? If so, are special fittings required?

The reason I ask is, at age 79, the 4500 psi tank is so much lighter and more easily carried to the range and to the dive shop.

Need your help, Please. Thanks. Richard

Greetings,

A friend dropped off his 4500 PSI tank for me to use.

It has a DIN fitting the same as my 3300 PSI tank and uses the adapter that comes with my Steyr Air Pistols.

It does work; HOWEVER, you need to use CAUTION and fill the cylinder slowly. Be prepared to shut off the valve quickly.

From a Safety viewpoint, I suspect the answer is NO.

Cheers,

Dave

I also use a 300 bar tank to fill the little pistol 200bar cylinders. I am VERY attentive as the valve on my tank has to be pushed in to close. I suspect that is to keep
from accidental closure in use by fire and rescue. Pushing the knob in can slightly bump the valve open causing a brief and very frightening increase in fill speed.

I am very cautious about this but it really isn't a big deal......

"Daystate PCP air rifle that requires a 4500 psi air source"

It may take a 4500psi source, but does it NEED one?

This is playing with fire.......
If you must just fill your 300 bar tank to 220bar, it will cool to just above 200bar (3000psi)
and accept lower shot numbers from the rifle.
Play safe.

Rover has this one right!

Many Daystate rifles are filled to either 232 BAR, or 250 BAR. If they are regulated, they do not need to be at either rating, as the regulator controls the exit pressure. Basically, 200 BAR will work, you just get less shots.

My understanding is that dive shops can fill both 200 BAR and 300 BAR tanks, quickly, because of their cascade systems. Too much green involved, for me at least. I stick with 200 BAR, and let the regulators do their work in rifles that can use 300 BAR.

I have heard that there is a valve system that will allow one to fill 200 BAR tanks, from a 300 BAR tank. That info was from Airguns of Arizona, and I did not explore it.

Maybe, just have your dive tank readly to fill lots of air pistol cylinders, and your scba tank ready to fill the rifle?

There are regulated fill set-ups available but much cheaper is the one way flow restrictor. This greatly slows the fill process. All the same, one swell foop and at the least, you have a damaged tank. That is the best outcome. Best to be very cautious.

There's already been plenty of good replies to this, but as someone who has worked in the industry, I figure I might as well chime in.

So first of all, the 'official' answer, of course, is NO, NEVER DO IT, YOU'LL DIE!

Now that that is out of the way, the real answer is YES, it is possible, and MAYBE you'll need different fittings.

The best way to do it is to use a regulator to make sure the 3000psi pistol never sees >3000psi. However, regulators are expensive, and are overkill. As everyone has already said, the key is to fill slow enough (AND USE A GAUGE) that you can react to shut of the valve before your pistol hits 3000psi. This can be done by just 'cracking' the valve on the tank, but they also make restrictor fittings that have a very small orifice to keep the flow rate low.

As I think Rover implied, you don't HAVE to fill your 4500psi tank all the way to 4500psi either. Yeah, you won't get as many fills out of it, and you won't be able to fill your rifle completely (fewer shots), but that's probably the safest option here.

As far as special fittings, that depends entirely on your tank, I think. If you are using a scuba tank with a 'standard' yoke or DIN fitting, then it will likely be different than the 4500psi air tank. If you are using a standard carbon fiber SCBA respirator tank, it will likely have a CGA347 valve, which is different from scuba.

marky-d

Ok, you guys know that there is a GLARING safety concern with partially filling a 300 bar tank to 200 bar. YOUR EYEBALLS NEED TO SEE IT HAPPEN. I drop my tank at the dive shop and pick it up serviced. Its a 200 bar tank. Normal fill. If you ask your dive shop to short fill the tank, and thats not their normal procedure, you are asking for issues if you assume its only at 200 bar and its not. It is probably safer to go thru the process of makind a special low flow tank adapter and accepting the fill risk than to trust that a dive shop would deviate from tbeir normal safe approved industry standard ansi compliant methods......

The problem with dive shops is that you do not always get what you pay for. The last fill I got at a dive shop one tank was a full 200 BAR, and the second tank was at 188 BAR. You get whatever the kid filling that day has time for, in between texting his girlfriend and picking his nose.

I gave up and bought a compressor.

If you have a 4500psi SCBA tank and a foster fitting at the end of your microbore hose get something like this for filling pistol cylinders:
https://www.pyramydair.com/s/a/Air_Vent ... nnect/5358
or a nice one piece machines stainless adapter "DIN200/DIN300 to Male Paintball Quick Disconnect" from airtanksforsale.com.

Bought my 4500psi SCBA setup from Joe B (airtanksforsale.com) and get it filled for free at a fire station (need the fire station adapter) cause they also use 4500psi SCBA and some dive shops can't do better than 3000psi. BTW, the fire station compressor is impressive: natural gas powered compressor filling a 6000psi cascaded resevoir that is then used to fill several SCBA bottles at a go.

My SCBA tank config is pretty typical for PCP shooters and has two gauges: tank pressure (small) and line pressure (large & accurate). Open main valve slowly to fill AP cylinder such that large gauge needle moves slowly. It isn't touchy but do have to pay attention. Close main valve at 200bar. Allow to cool. Top off. Close main valve, open bleed valve, disconnect cylinder. Use of the bleed valve is not possible for some cylinders as the fill adapter presses the valve open, remove adapter to close.

In the hunting PCP forums nearly the only time a regulator is used at the tank is when shooting tethered. Bench rest shooters commonly do this.

Of course there are no such concerns with an SSP. :-)

https://www.ebay.com/itm/272957931990

People don't seem to want to get a regulator, but there are a number of 4500psi input 3000psi output regulators for paintball.