Taking bets?

[BigEvil]

One of my guys recently gave me a 4500 firemans SCBA tanks very similar to this one;


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I THINK its 66 cu ft (the same as the one above). Im just in the process of tracking down the appropriate fittings to reduce the scba valve down to the 1/8 npt nipple we use.

So, how long do you think something like this would take to fill to 4500 with the Shoebox ?? My guess is 34 hrs. (I pulled that number out of thin air btw)

[DoubleDutch]

I think it will take 19.8 hours to fill. I am basing that on a guess that SCBA tank capacities are given in the same way as SCUBA tanks, which is the volume of air at ambient pressure that will fit in a given tank, when filled to capacity. This is different than paintball tanks, which are given in actual volume of the tank.

So, (66/80)x24 = 19.8 hours

And you should be able to just buy this fill adapter, and connect you SCBA straight to the male QD on the shoebox. Then you can use it to fill your tank too.
http://www.scubacompressor.com/shop/...e91196cbf7f68f



On a different note, WOHOOOO !!!!!!!!!!

Yuk,

Here's your tracking # 1Z2291T10393567069
Scheduled delivery is tomorrow 6/25/10

thanks so much!

Carol

Tuna, we need them hose kits!!!

[cockerpunk]

you should get a really big drop forward for it. ON GUN AIR BABY!

[xero28]

I think it will take 19.8 hours to fill. I am basing that on a guess that SCBA tank capacities are given in the same way as SCUBA tanks, which is the volume of air at ambient pressure that will fit in a given tank, when filled to capacity. This is different than paintball tanks, which are given in actual volume of the tank.

So, (66/80)x24 = 19.8 hours

Yes, but that's based on 3000 psi. So, if we're using that logic:

4500/3000 = x/24

x = 24(1.5)

x=36

66/80 = x/36

x = 36(.825)

x = 29.7 Hours to fill 66 Cubic feet to 4500 psi.

[DoubleDutch]

Yes, but that's based on 3000 psi. So, if we're using that logic:

4500/3000 = x/24

x = 24(1.5)

x=36

66/80 = x/36

x = 36(.825)

x = 29.7 Hours to fill 66 Cubic feet to 4500 psi.

Nope, I disagree. My point was that the way SCUBA tank capacities are given is irrespective of the fill pressure. A basic 80 cu ft aluminium SCUBA tank at 3000 psi will hold air that will expand to 80 cubic feet if let out at ambient. A 66 cu ft SCBA tank at 4500 psi will hold air that will expand to 66 cubic feet if let out at ambient. Basically it correlates to the number of molecules you can stuff into the tank at the rated pressure. So, the 80 cu ft and 66 cu ft numbers already has both the volume and the pressure of the tank factored in, and assuming a linear fill rate on the compressor, the ratio of these two number should be the same as the ratio of the time it takes to fill either tank.

This way of showing the capacity of tanks is important to SCUBA/SCBA users, as it directly correlates to the number of breaths they can take when it is regulated down to ambient by their first and second stages. So when selecting a SCUBA tank, a diver doesn't have to look at both the cu ft and the pressure the tank is rated to, only at the cu ft. You can get SCUBA tanks that are rated anywhere from 2240 psi to 4400 psi, so it pays not to have to do the math when determining how much air you need, just look at the cu ft (and weight of course).

[xero28]

Nope, I disagree. My point was that the way SCUBA tank capacities are given is irrespective of the fill pressure. A basic 80 cu ft aluminium SCUBA tank at 3000 psi will hold air that will expand to 80 cubic feet if let out at ambient. A 66 cu ft SCBA tank at 4500 psi will hold air that will expand to 66 cubic feet if let out at ambient. Basically it correlates to the number of molecules you can stuff into the tank at the rated pressure. So, the 80 cu ft and 66 cu ft numbers already has both the volume and the pressure of the tank factored in, and assuming a linear fill rate on the compressor, the ratio of these two number should be the same as the ratio of the time it takes to fill either tank.

This way of showing the capacity of tanks is important to SCUBA/SCBA users, as it directly correlates to the number of breaths they can take when it is regulated down to ambient by their first and second stages. So when selecting a SCUBA tank, a diver doesn't have to look at both the cu ft and the pressure the tank is rated to, only at the cu ft. You can get SCUBA tanks that are rated anywhere from 2240 psi to 4400 psi, so it pays not to have to do the math when determining how much air you need, just look at the cu ft (and weight of course).

Hmmm, interesting. I didn't know that about SCUBA tanks. So, you're saying that an 80 cu ft 3000 psi tank will take just as long to fill as an 80 cu ft 4500 psi tank?

[DoubleDutch]

Hmmm, interesting. I didn't know that about SCUBA tanks. So, you're saying that an 80 cu ft 3000 psi tank will take just as long to fill as an 80 cu ft 4500 psi tank?

Exactly. Same amount of air, smaller volume for the 4500 psi one.

The benefit is that the 4500 psi tank would be smaller. Not necessarily lighter, as it might require thicker walls. Luxfer has a 106 cu ft carbon fiber 4350 psi SCUBA tank that is about the same size/weight as an aluminum 80 cu ft 3000 psi tank. It costs more than the Shoebox though.

[BigEvil]

you should get a really big drop forward for it. ON GUN AIR BABY!

That is kinda what im thinking LOL

[DoubleDutch]

[QUOTE=joeyt]

http://www.scubacompressor.com/shop/paintball-adapter-with-inch-hose-p-100.html?osCsid=ba579e8586203165bae91196cbf7f68f[/url]

would this connector work as well? a little cheaper... ($75)

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

I can't tell if it is a CGA 347 fitting, which is what most SCBA tanks have as an output. It could possibly be a 7-thread DIN, which is a SCUBA fitting rated up to 4500 PSI.

Even if it is a CGA 347 input, note that it doesn't have a purge valve. Filling a SCBA tank from the Shoebox would not be a problem, as the Shoebox has a purge, but your PCP tank must have a purge in order for you to fill it from a SCBA tank with this adapter. Our Paintball tanks don't have purges, so this would not work, there would be no way to depressurize the line. Note that their mini tanks have a purge button built into the valve, so if you had one of their tanks it would be ok.

Actually, looking at the price difference, it looks to be about what a separately purchased purge valve would cost.

See the 88 cu ft tank they have on there? That would be a nice storage tank to have, more air than a SCUBA, and 4500 psi to start with. Even comes with all the hoses! Only(!) $650!

Which brings me to something that has been bugging me... so the In-flight refueling hose that Ninja sells, is marked as rated to 4500 psi, but apparently not for constant use. How can you tell what is OK for the amount of time the shoebox might be subjecting the hose to? Do you just need to get something that is rated to 8000 psi or something? If you bought this Airhog 88 cu ft tank with the hose assembly, you would know that the hose can handle 4500 psi while filling, but how would you know if it was ok to sit with up to 4500 psi in it for 19 hours?

EDIT: Hey! Where did you post go?

[BigEvil]

And you should be able to just buy this fill adapter, and connect you SCBA straight to the male QD on the shoebox. Then you can use it to fill your tank too.
http://www.scubacompressor.com/shop/...e91196cbf7f68f

Ah good link, thanks. They also have the fitting + bleeder w/o the hose

On a different note, WOHOOOO !!!!!!!!!!

I hate to break it to you, but guess what I got YESTERDAY

[DoubleDutch]

I hate to break it to you, but guess what I got YESTERDAY

No fair! I was ahead of you on the list! You only got that early because TK had your marker!

[BigEvil]

No fair! I was ahead of you on the list! You only got that early because TK had your marker!

OH CRAP I FORGOT ABOUT THAT!

[ezcreation]

http://www.scubacompressor.com/shop/...e91196cbf7f68f

Isnt that exactly what we would need for our scuba tanks??
Tuna can you let us know quick? I would rather purchase from you but need info asap
Thanks

[BigEvil]

http://www.scubacompressor.com/shop/...e91196cbf7f68f

Isnt that exactly what we would need for our scuba tanks??
Tuna can you let us know quick? I would rather purchase from you but need info asap
Thanks

That should work for filling scubas. To fill a bottle from the SB, you will still needs a hose with the proper rated quick disconnects on them.

[ezcreation]

http://www.scubacompressor.com/shop/...e91196cbf7f68f

for the hose

http://www.scubacompressor.com/shop/...e91196cbf7f68f

For the quick disconnect

Seems pricey but all rated 6000psi

[DoubleDutch]

http://www.scubacompressor.com/shop/...e91196cbf7f68f

for the hose

http://www.scubacompressor.com/shop/...e91196cbf7f68f

For the quick disconnect

Seems pricey but all rated 6000psi

Don't forget 2 reducers to 1/8 NPT
http://www.scubacompressor.com/shop/...e91196cbf7f68f

[DoubleDutch]

I too am hoping Tuna will come through. If he delivers a hose with gauge, and two female QD's at both ends, I think the most cost-effective solution, if you don't already have a SCUBA fill station, is to get the Yoke, bleed valve, and male QD separately from scubacompressor.com. Each unit will then have a male QD, then you can use Tuna's hose between them interchangeably. (Shoebox to SCUBA, Shoebox to paintball tank, SCUBA to paintball tank)

Actually, looks like you can get a Yoke and Bleed combo, then you only need a reducer to get it down to 1/8 NPT, and a male QD.
http://www.scubacompressor.com/shop/...e91196cbf7f68f

[wimag]

[QUOTE=DoubleDutch]

I can't tell if it is a CGA 347 fitting, which is what most SCBA tanks have as an output. It could possibly be a 7-thread DIN, which is a SCUBA fitting rated up to 4500 PSI.

Even if it is a CGA 347 input, note that it doesn't have a purge valve. Filling a SCBA tank from the Shoebox would not be a problem, as the Shoebox has a purge, but your PCP tank must have a purge in order for you to fill it from a SCBA tank with this adapter. Our Paintball tanks don't have purges, so this would not work, there would be no way to depressurize the line. Note that their mini tanks have a purge button built into the valve, so if you had one of their tanks it would be ok.

Actually, looking at the price difference, it looks to be about what a separately purchased purge valve would cost.

See the 88 cu ft tank they have on there? That would be a nice storage tank to have, more air than a SCUBA, and 4500 psi to start with. Even comes with all the hoses! Only(!) $650!

Which brings me to something that has been bugging me... so the In-flight refueling hose that Ninja sells, is marked as rated to 4500 psi, but apparently not for constant use. How can you tell what is OK for the amount of time the shoebox might be subjecting the hose to? Do you just need to get something that is rated to 8000 psi or something? If you bought this Airhog 88 cu ft tank with the hose assembly, you would know that the hose can handle 4500 psi while filling, but how would you know if it was ok to sit with up to 4500 psi in it for 19 hours?

EDIT: Hey! Where did you post go?

it is a CG347. I have the male counterpart with 1/8 nipple to fill off the cascade system at my fire department.

[PBChappy]

how long would it take to fill
http://www.scubacompressor.com/shop/...86781d7f49636a

and would it be to much for the shoebox to handle?

[Tunaman]

My setup will be way cheaper than that and higher rated. I am just waiting for the proper QD's to get here. I don't have enough in stock yet. Any day now.

[Tunaman]

how long would it take to fill
http://www.scubacompressor.com/shop/...86781d7f49636a

and would it be to much for the shoebox to handle?

You will have to do that test yourself, but yes...the shoebox will fill it.