Page 1 of 2

Scuba tank setup for air pistol cylinder refills

Posted: Wed May 29, 2024 5:41 pm
by crsuribe
Hello, I ordered a Feinwerkbau P8X and have ZERO previous experience with PCP. Figured it's going to take 3, to 4 months for the pistol to get here so I might as well figure out everything else I'll need to use it.

I have read just about every thread here on the subject but still don't seem to understand exactly what I need.

Here are my main points of confusion:
  • The pistol's cylinders take 200bar/3000psi - from what I've read, I would want something that can hold pressures higher than 3000psi because, otherwise, only the first refill will be at 3k psi?
  • I need some kind of regulator valve to ensure that only 200bar/3000psi is dispensed into the pistol's cylinder if the tank is loaded to higher pressures?
  • I have to be careful not to overfill my pistol's cylinder, and need to make sure to open the tank's valve slowly?
  • What is an ideal size of scuba tank to keep at my house so I can refill the pistol ahead of any matches? 80cu ft?
  • Steel vs aluminum?
  • My local shop charges $10 a refill and my pistol takes about 97cc at 200 bar, I would like to buy something that gets me lots of fills without having to go to the scuba shop to get my tank refilled all the time
  • Anything else I should know or consider?
Thanks in advance for your help!

Re: Scuba tank setup for air pistol cylinder refills

Posted: Wed May 29, 2024 6:40 pm
by brent375hh
I used 80 cubic foot tank for years. It goes down a little every time, but you probably get 3 months shooting every day before it won't get 100 shots from a fill.

Going to a higher pressure tank would certainly be risky without an intermediate regulator, of which I have not seen anyone use.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Wed May 29, 2024 7:26 pm
by fc60
Greetings,

Since the tank will be static, no diving and carrying it around, consider a 100 CFT tank.

They can be filled to 3300 PSI and you will get a lot of fillings.

Also, look into a used tank at the local dive shop. Just be sure it has been Hydro tested recently; or, have it done at purchase time. Hydro tests are every five years.

Oh yes, ask for a DIN 200 fitting to match your Feinwerkbau filling adapter. Here I go on memory so double check me. Or, take a friends fitting to the dive shop for proper fitment.

Cheers,

Dave

Re: Scuba tank setup for air pistol cylinder refills

Posted: Wed May 29, 2024 7:43 pm
by Gwhite
Depending on your age & physical condition, I would recommend only an 80 CF tank. I'm in my early 70's, and can handle an 80 just fine, but the 100 is just big & heavy enough that I dread wrestling with them. The team I help coach has a couple of each.

Unless you shoot a LOT, an 80 should last a long time. Most of our air pistol average about 1 bar per shot out of the cylinders. You can get sighters & a full 60 shot match with the pressure down to around 140 bar. It takes a long time to drop a 80 CF tank down that far.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 4:42 am
by JamesH
I don't think I've heard of anyone using a regulator to reduce from above 200 bar eg 300 bar to 200 bar.

Normally the pistol cylinder adaptor will only fit the correct size scuba cylinder outlet (200bar and 300bar scuba cylinders have different threads so they can't be mixed up in the field) so you'd need a regulator AND an adaptor.

The simplest and safest option is to get a 200 bar cylinder, if you want it to last longer get a bigger one.
If you are not happy with 'only' getting 100 shots out of your pistol as your scuba cylinder runs down get it topped up more often - I think scuba shops charge less for a top up than a full tank.
I think they charge more to fill a 300 bar tank than a 200 bar tank so apart from travel to the shop you're not saving money.
You can also reduce the velocity of your air pistol a bit and use less air that way.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 6:43 am
by Rover
If all this troubles you, you might want to consider having a large nitrogen tank (or two) delivered. When it gets low, just pick up the phone and they'll swap it out on a full one.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 7:46 am
by alpineboard
I fill my own 80 cu ft scuba tank to 3000 psi, with a "Yong Heng" dual stage air compressor with filters. The Yong Heng will go to 300 bar, 4000 psi , but my tank is a aluminum 3000 psi, and that is all I need. The 4000 psi tanks are big $$.
The Yong Heng is approx $300 at amazon, try to get the real authentic Yong Heng, The questions that you ask, many answers are at "AirgunNation"
There is a specific thread on Yong Heng.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 8:16 am
by crsuribe
Considering the recommendations so far, what about something like this?

https://www.champchoice.com/mc-airgun/f ... -80-cu-s80

Is that about everything I'd need?

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 10:07 am
by Gwhite
Buy a used 80 CF tank at a dive shop with a "K" valve, and put the money you save towards a decent fill adapter setup. The pressure gauges on cylinders are notoriously inaccurate, and unscrewing cylinders under pressure will cause extra wear on the threads. The team I help coach uses 3 of these setups with bleed valves and high quality gauges:

https://www.bestfittings.co.uk/shop/air ... ton-bleed/ (use the "No Hose" option)

https://www.bestfittings.co.uk/shop/fil ... -bsp-male/

You will need a copper washer to connect the two, which they will likely throw in for free.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 11:42 am
by crsuribe
Gwhite wrote: Thu May 30, 2024 10:07 am Buy a used 80 CF tank at a dive shop with a "K" valve, and put the money you save towards a decent fill adapter setup. The pressure gauges on cylinders are notoriously inaccurate, and unscrewing cylinders under pressure will cause extra wear on the threads. The team I help coach uses 3 of these setups with bleed valves and high quality gauges:

https://www.bestfittings.co.uk/shop/air ... ton-bleed/ (use the "No Hose" option)

https://www.bestfittings.co.uk/shop/fil ... -bsp-male/

You will need a copper washer to connect the two, which they will likely throw in for free.
Do you know if there is a source for those parts in the U.S.? I called a scuba shop and they have a used 80CF with new hydro and inspection for $175 so I had them set it aside for me but would need the other parts and would love it if I don't have to wait for shipping from UK

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 11:50 am
by Gwhite
Unfortunately, they are the only place on the planet that does such a nice job on this stuff. The shipping is pretty quick.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Thu May 30, 2024 12:23 pm
by crsuribe
Gwhite wrote: Thu May 30, 2024 11:50 am Unfortunately, they are the only place on the planet that does such a nice job on this stuff. The shipping is pretty quick.
Sent you a PM with further questions. I hope you don't mind. Thank you for your help!

Re: Scuba tank setup for air pistol cylinder refills

Posted: Fri May 31, 2024 6:36 am
by Rover
It's not too late to cancel your order and find a nice single stroke pneumatic, thus saving all this stress, aggravation, and expense.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Fri May 31, 2024 7:18 am
by alpineboard
I chose to get the compressor and fill my own, reasons being, not any round trip travel time to and from a fill station, also considering the fill is only a top off fill. I regularly fill the tank once a week in the outdoor warm season, due to the more air used per shot with an FX Crown outdoor air rifle.
For indoor 10 meter AR, 2 tanks last an entire indoor season, for 2 shooters, pretty much 7 days a week/eves usage.
The compressor will pay for itself in time, due to this no travel for a fill situation. Also, if you hunt around enough, you can find tanks for free.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Fri May 31, 2024 8:26 pm
by seamaster
https://www.amazon.com/GX-Pump-Oil-Mois ... 673&sr=8-1

After my Hill Pump died, I seriously try to get a PCP tank and GX compressor.

Finally, settled in this hand pump, thinking just give hand pump one last try, if it dies, just throw it away. It is cheap enough to have no regret. If it dies, I would go PCP tank after that, no regret.

WOW, I am wrong! I got blown away by this hand pump, so smooth, so easy to get up to 3000ps ! Much better than any of three Hill pump I had earlier !

No regret trying this last hurrah at hand pump.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Fri May 31, 2024 9:09 pm
by crsuribe
I wanted the clean air from a scuba shop, I know it probably doesn't matter but I feel better using the cleanest dryest air possible

Re: Scuba tank setup for air pistol cylinder refills

Posted: Sat Jun 01, 2024 4:19 am
by masaki
Have you ever checked SCBA tanks? SCBA tank is lighter, higher pressure thank SCUBA tanks.
https://www.youtube.com/watch?v=ypyq-1MaSlc

I have been using SCBA tank made of CarbonFiber-Reinforced Plastic 300bar tanks for either of my 300bar and 200bar pistols. It does not equipped with regulator, but you can safely refill 200-bar cylinder from 300-bar mother tank by opening the valve little by little as you watching the gauge.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Sat Jun 01, 2024 8:56 am
by Gwhite
There are several issues with fiber tanks vs SCUBA tanks. The inspection schedule & life are different, and the higher pressure rating of SCBA tanks needs to be dealt with carefully.

SCUBA tanks can re-tested & recertified pretty much forever. Most dive shops require an annual internal inspection on SCUBA tanks, and they must be hydrotested every 5 years. If you are lucky, some shops will wave the annual inspection if you swear the tank will never go near the water, and not be used for breathing.

SCBA tanks are also supposed to have an annual inspection. It's possible that paint ball shops ignore that because it's not for breathing. Fiberglass SCBA tanks must be hydro tested every 3 years, although the newer carbon fiber ones are good for 5 years. The tanks expire after 15 years from date of manufacture. You can get a life-extension re-recertification done every 5 years after that to use them for another 15 years.

The costs of all the testing can vary wildly. There are dive shops that will do an annual inspection (with a fill) for $20. The only shop around me charges $25 for an inspection, and $60 for hydro testing. I've seen prices on-line for as much as $90 for a hydro. I don't have any pricing on SCBA fills at a paintball shop, but the prices I saw for life extension testing for fiber SCBA tanks was astronomical (> $300). You'd be better off buying a new tank.

One big issue for me is safely filling a 200 bar rated air pistol cylinder from a SCUBA or fiber tank with as much as 300 bar in it. If you get the appropriate valve on it, dive shops will only fill a SCUBA tank to 200 bar. Even if you are really careful, having a 300 bar tank increases the risk of a nasty accident. I've looked several times over the years to see if anyone has an inexpensive fixed regulator that would drop a high pressure tank down to 200 bar, but I have yet to find one. Best Fittings in England has a nice regulator, but it's fully adjustable, with two big gauges, and costs almost 400 GBP if you get the anti-tamper cap.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Sat Jun 01, 2024 7:02 pm
by Oldnslow
It's really not that big a deal to use a hand pump to fill PCP pistol cylinders to 200 bar. See for example our host's website under Essential Information. The cheap Chinese hand pumps available on, e.g., Amazon work as well as any others.

Re: Scuba tank setup for air pistol cylinder refills

Posted: Sun Jun 02, 2024 4:03 am
by deadeyedick
I have owned both 200 and 300 bar cylinders and preferred the 300.
You have to watch closely when transferring from the 300 to a 200 AP cylinder to ensure not going over pressure but apart from that it lasts much longer.
The threads are the same on both, however the thread is about 5-6 mm longer on the 300 bar and I had to machine an insert to take up this extra thread length.