Bank Bottles, are they really worth it?

[Jeff Pack]

I just priced the parts to plumb in my bank bottles, and I'm around 800$ in parts, plus 800$ in bank bottles(2).

What do I really gain for that amount of money?

Sure I could bank nitrox, or air, but all I gain in either is not having to fire up the compressor. Its still the same compressor time to fill them, versus direct to my scuba tanks.

Am I missing something?

[kdupreez]

Yeowza! That's expensive!

How many bank bottles do you have?

Should not be more that about $250 to plumb 4 of them.. excluding fill whips..

Are you going all stainless?

Bank bottles reduces compressor wear and increases filter lifetime and also makes filling more convenient and efficient time wise.. especially if you can cascade.

If you bank 32% its obviously very convenient.

[Jeff Pack]

230$ alone for the regulator, 43$ each for line valves, CGA nuts at 23$ each, check valves(43each), T's, manifold, it all adds up fast.

And thats mail order prices.

And thats not even priced in the SS tubing yet to plumb it.

[Jeff Kruse]

Bank bottles reduces compressor wear and increases filter lifetime and also makes filling more convenient and efficient time wise.. especially if you can cascade.

.

Please explain as I could never understand this.

I can see banking as a way of making PP Nitrox. I can see banking as a way to run your compressor when you have time thus not having to run it when you don’t have that time.

I see banking as a way to make the compressor run harder not easier.
If you need to fill to 3500 your bank needs to be higher thus making you run your compressor longer at the higher pressures.

I think using a bank makes your compressor have to run longer at the higher pressures.

[CaptnJack]

230$ alone for the regulator, 43$ each for line valves, CGA nuts at 23$ each, check valves(43each), T's, manifold, it all adds up fast.

And thats mail order prices.

And thats not even priced in the SS tubing yet to plumb it.

You don't need a regulator or the check valves.
You need a manifold, Ts and one line valve per bank bottle.

You can get the CGA nuts and nipples waaaay cheaper on ebay.

Just 2 bank bottles is not very helpful. You want something of a cascade with the bulk of the storage at lower pressures and less at medium and high pressures. I have
800cf at 2400psi (3 bottles)
750cf at 3600psi (2 bottles)
900cf at 4500psi (2 bottles)
I got all the bottles used, and they have a variety of valves on them.

The 4500psi bank is really hard on the compressor, you don't want to be topping that up just to dump it into a nearly empty tank. I use my banks for a couple of things 1) to be able to quickly refill or partially refill a bunch of tanks 2) to avoid running my compressor on the hottest days 3) as a reservoir to be able to use up the last of an O2 bottle so I can get more at a convenient time intead of having it go empty on a sunday when I need it.

[boydski]

Bank Bottles are very convenient if you have a lot of tanks to fill in a short period of time. For example, you had a great dive on Saturday, arrived home late and need to refill a bunch of tanks for an early Sunday morning dive. Banked gas would mean you don't need to run the compressor for hours late on a Saturday night.

On the flip side, if you only have a few tanks to fill (i.e. your own and not dozens of your buddy's), it is often just as easy to flip on the compressor for 15 minutes and top off your tanks. I don't bank gas and fill straight from the compressor as needed. As a result, I do not run my compressor for long periods of time, which keeps the heat (and wear/tear) down. I also have lots of tanks, so would simply grab an extra pair (already full) in the scenario above.

YMMV, Good Luck,

[CaptnJack]

At 3.5cfm I'm not filling anything beyond an al40 in 15mins!

[boydski]

At 3.5cfm I'm not filling anything beyond an al40 in 15mins!

Richard, are you saying that it is too small?

Sorry, I just couldn't resist!

[CaptnJack]

At 3.5cfm I'm not filling anything beyond an al40 in 15mins!

Richard, are you saying that it is too small?

Sorry, I just couldn't resist!

Hah were you talking to Sounder?

[Jeff Pack]

230$ alone for the regulator, 43$ each for line valves, CGA nuts at 23$ each, check valves(43each), T's, manifold, it all adds up fast.

And thats mail order prices.

And thats not even priced in the SS tubing yet to plumb it.

You don't need a regulator or the check valves.
You need a manifold, Ts and one line valve per bank bottle.

You can get the CGA nuts and nipples waaaay cheaper on ebay.

Just 2 bank bottles is not very helpful. You want something of a cascade with the bulk of the storage at lower pressures and less at medium and high pressures. I have
800cf at 2400psi (3 bottles)
750cf at 3600psi (2 bottles)
900cf at 4500psi (2 bottles)
I got all the bottles used, and they have a variety of valves on them.

The 4500psi bank is really hard on the compressor, you don't want to be topping that up just to dump it into a nearly empty tank. I use my banks for a couple of things 1) to be able to quickly refill or partially refill a bunch of tanks 2) to avoid running my compressor on the hottest days 3) as a reservoir to be able to use up the last of an O2 bottle so I can get more at a convenient time intead of having it go empty on a sunday when I need it.

I do need a check valve, as out of the compressor is a distro block, of which one line goes to 2 line valves to fill tanks, another line would go to the banks, thus a check valve is needed there, or the banks backfill the distro block.

I dont understand why I wouldnt need a regulator, although I "suppose" coming off the bank I could just use a line valve to control pressure to the tanks? (Instead of a regulator?)

I was just going to use the bank for either fast fills if needed, or topping off tanks. Or I guess if a really hot/humid day.

[CaptnJack]

I don't use a regulator. That's only needed if you want to walk away for awhile.

I don't understand your distribution block issue. My compressor feeds into my manifold. 2 whips come off to go to tanks with a guage on the manifold, 3 taps come off to go to my banks. One line valve and one gauge per bank. There's no check valve needed except the backpressure valve (which is a check valve) right after your final filter tower.

[Jeff Pack]

maybe I'm missing something, but that distro block has 2 air sources to it, the compresser, and the bank(backfilled from bottles). If the compressor isnt running, the banks are backfilling the distro block, thus its always under pressure. So if I hook up 2 scuba tanks, open the line valves, wont they be fed from the banks?

The check valve keeps that bank line from backfilling the distro block.

Oh wait, I see with yours, you dont need the check valve, because you can shut off your tanks, and accomplish the same thing without a check valve.

Except the line valves are more exspensive (2 of them @43$ each), versus 1 check valve at 23$.

Although in my case, couldnt I get away with 1 line valve, which would shut off both bank bottles at once? (or open them)

[Jeff Pack]

Would this work?

[CaptnJack]

You can't just put a check valve between the manifold and the bank bottles, you won't be able to use them if you did!

You could shut off the bank bottles at their valves and save on line valves. Its nicer to have all the valves together though.

[Jeff Pack]

the check valve is only betweenthe compressor and the manifold. The bottles only have a line valve.

[CaptnJack]

the check valve is only betweenthe compressor and the manifold. The bottles only have a line valve.

And which way does that check valve allow flow?


(hint its a trick question

[Jeff Pack]

check valve flows towards the manifold (from compressor), that way there's no reverse pressure on the compressor. Now I dont know if that is actually needed, from what you previously posted about the back pressure valve on the compressor.

[Dusty2]

Replace the check valve between the compressor and the manifold with a line valve and it would work fine for air fills. If your doing HP fills you might consider a haskel pump for topping off instead of doing it with the compressor but that's another big expense that you probably don't need.

[Jeff Pack]

true, but line valves are almost double the cost of a check valve... (23 v 43)

[CaptnJack]

the backpressure reg is already a check valve you can skip it.
although if you are worried about a $20 difference you need to readjust your Mr Gadget barometer :luv:

[Jeff Pack]

but thats 20$ towards YAST (Yet Another Shiney Thing) !!

[CaptnJack]

but thats 20$ towards YAST (Yet Another Shiney Thing) !!

very true but all those knobs and stuff are cool! I will try to remember to post some pics of mine.

[Jeff Pack]

that would help, give me some layout ideas, I'm going to try this myself and see if I can do it. I'm not very handy with this kinda stuff.

[ljjames]

http://pontificatingnobody.com/Denton-FillStation/


http://thedecostop.com/forums/showthrea ... g-stations

and from that thread

David Swift's plans based on Dentons

[Jeff Pack]

With a 5cfm compressor, am I better to have just 2 fill whips, or extend to 4? Or does it really matter, cummulative time is the same.

One could argue its better to go out after 35m, than leave it for an hour.