Gx cs4-i and omega 75 cuft tank

I filled 4 60 minute SCBA tanks from empty with mine. I gave it plenty of breaks and purged the water about every 20 minutes. Each tank took me the better part of a day, but I did give it lots of breaks.
Im going to sound dumb.. but what's a "60min" tank ..,? Like in volume , 40 cf ?, 9 liter,?
 
Im going to sound dumb.. but what's a "60min" tank ..,? Like in volume , 40 cf ?, 9 liter,?

There are many words used to describe SCBA tanks, some of them aren't very accurate, like "minutes" (30/45/60). That term is typically used by firefighters who use them to breathe from. (But what isn't taken into account is the "state" of the breather; are they resting? Exerting themselves? Heavily exerting?)

Another misnomer is calling a SCBA tank a 45/66/88 cu ft tank. Again, air is compressible, so add more pressure, and you get more air volume. Not very accurate, yet many refer to their Great White tanks from topairguns as 97 cu ft.

A more accurate nomenclature is the water volume; this tells how big the tank actually is, since air is compressible, and the more pressure, the more air it holds.

The biggest SCBA tanks commonly sold are 550 cu in, or 9L water volume. Some also call these 97 cu ft (air volume), or 60 minute tanks. Joe Broncato clearly lists his tanks by size, take a gander at his site (also HIGHLY recommend buying from him; the tanks are not cheap knockoffs that are expired, but top-notch tanks that meet DOT transportation requirements).

Guppy - 114 cu (1.9L) in or <<20 cu ft (not very accurate, but close enough for gubmint work)>>
Tiger Shark - 410 (6.7L) cu in or <<74 cu ft>>
Great White - 550 cu in (9L) or <<97 cu ft>>

HTH
 
@Baldone, don't be concerned about filling your Omega tank with a GX-CS4. Your Omega 75cf tank actually holds 66cf, not 75cf. It has 6.8 liters of inside volume. The 75cf rating is advertising hyperbole by the seller. The manufacturers of fireman's air tanks like Scott and Luxfer calculate actual compressed air capacity and rate a 6.8 liter tank at 66cf @ 4500psi. They also rate a 9 liter tank at 88cf capacity at 4500 psi. The reason for the lower capacity is that air compresses at a lower volume once pressure exceeds 3000 psi.
 
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There are many words used to describe SCBA tanks, some of them aren't very accurate, like "minutes" (30/45/60). That term is typically used by firefighters who use them to breathe from. (But what isn't taken into account is the "state" of the breather; are they resting? Exerting themselves? Heavily exerting?)

Another misnomer is calling a SCBA tank a 45/66/88 cu ft tank. Again, air is compressible, so add more pressure, and you get more air volume. Not very accurate, yet many refer to their Great White tanks from topairguns as 97 cu ft.

A more accurate nomenclature is the water volume; this tells how big the tank actually is, since air is compressible, and the more pressure, the more air it holds.

The biggest SCBA tanks commonly sold are 550 cu in, or 9L water volume. Some also call these 97 cu ft (air volume), or 60 minute tanks. Joe Broncato clearly lists his tanks by size, take a gander at his site (also HIGHLY recommend buying from him; the tanks are not cheap knockoffs that are expired, but top-notch tanks that meet DOT transportation requirements).

Guppy - 114 cu (1.9L) in or <<20 cu ft (not very accurate, but close enough for gubmint work)>>
Tiger Shark - 410 (6.7L) cu in or <<74 cu ft>>
Great White - 550 cu in (9L) or <<97 cu ft>>

HTH
Ya, I figured what's the he point in minutes .. like 60 minutes yoga breathing or 60 min panic stressed out breathing..lol. That make a big difference in a sizing ..lol
 
Im going to sound dumb.. but what's a "60min" tank ..,? Like in volume , 40 cf ?, 9 liter,?
This should help. I posted this chart in a thread sometime ago.

tanksizesrevised.jpg
 
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When I was doing a lot of diving I found that having the tank size rated in CF was useful. I knew that 120 CF would be good for a 60 minute dive at 60 feet with a comfortable amount left over for any safety stops or emergencies. The tanks might be of different volumes or different pressures, but the rating in cubic feet would give me a very good idea of how much dive time I would get.

As F6Hawk mentioned, the rating in minutes doesn't make anywhere near as much sense. Everyone is different and a 250 lb weightlifter working hard in a high stress situation could easily go through four times as much air as a 150 lb runner who's not exerting himself to the same extent.
 
I would simply set my shutoff pressure to what I guessed would take 1/2 hour less, go out and do some work or do some shooting and then come back in 45 minutes or so when the pump should have shut off. At that time I’d drain the water buildup, check the coolant temperature with my fingertip, choose a new shutoff level and do it all over again.
 
Thanks, guys, for the replies they all do help! I know you say when filling and giving the pump a bunch of breaks. Can you explain your filling process a little more in detail?

When filling, I never leave the area for more than 5 minutes. If filling for say an hour, I "burp" the bleed valve every 8-10 minutes or so to keep the water chamber empty. I've never run it for more than an hour at a time before shutting it down and letting it cool for 3-5 minutes (fan and pump running only).