Laying CO2 bottles down

[Owly055]

The topic of laying a CO2 bottle down came up on one of my threads..... Actually I had been mulling the issue during the day and came home to find the comment.

My thinking is that a regulator responds to pressure by opening or closing a needle valve.... or other type of valve. The diaphragm opens the valve when the pressure drops and closes it when it rises..... A valve doesn't know weather it's regulating a gas or a liquid..... But we all know "size matters"........ whatever anybody says to the contrary.

That thinking leads me to the conclusion that sensitivity will be lost as size increases..... or is it the other way around ;-) In the final analysis it would seem not to really matter that much.... We aren't feeding air to astronauts or scuba divers,but CO2 into beer. I suspect that we can tolerate significantly more moment to moment fluctuation than can be tolerated in those kinds of applications.

Opinions as they say out here are like A______s........... Everybody has one. Mine's not worth a hill of beans until I try it,

I'd like to hear from folks who have actually done this. Laying a CO2 bottle down is NOT a new idea. I lay my oxygen, and nitrogen bottles down all the time..........Never my acetylene bottles for obvious reasons........ Obvious if you are a welder anyway. I don't lay propane bottles down..... unless I want liquid, and with the new bottles I can't do that anymore on anything less than a 100 pounder. In most non-automotive propane applications you don't want liquid......but I'm not "most people", and often use things in unconventional ways.

What's your experience laying down a CO2 bottle ( with beer ).


H.W.

 

[bja]

An excerpt from this site http://www.warpig.com/paintball/technical/gasses/co2dynamics.shtml#3

"A "full" tank contains about 34% liquid CO2. If it is filled any more, the CO2 will become very sensitive to temperature changes, with a small increase in temperature causing a large increase in pressure. This is a dangerous situation which is avoided by only partially filling the CO2 bottle. "

If this is true, the liquid co2 will still be below the outlet valve when laying a bottle on it's side and all should be fine.

 

[SnakeRidge]

I use 10# O2 bottles at work. I've got a cart that I lay them down on horizontal and I was told by a lab inspector that keeping them that way could corrode the regulator. I kinda feel like that's BS. The tank is steel and the regulator is stainless so wouldn't any corrosion be faster on the steel?

 

[Owly055]

I use 10# O2 bottles at work. I've got a cart that I lay them down on horizontal and I was told by a lab inspector that keeping them that way could corrode the regulator. I kinda feel like that's BS. The tank is steel and the regulator is stainless so wouldn't any corrosion be faster on the steel?

I would second your opinion on that...... Oxygen in normal bottles is a gas, not a liquid. LOX bottles are far different, and only used by people who are using a LOT of oxygen, as you can't keep it liquid under a reasonable pressure...... they use evaporative cooling to keep oxygen in a liquid state...... That means that if you don't use it fast enough, it will vent. You see these large tanks, usually stainless steel with a protective rail around them in the backs of scrapper's pickups. I believe the actual pressure vessel is contained within, and what you are seeing is an outer shell with insulation between.... perhaps even a vacuum chamber as is used with liquid nitrogen. Liquid nitrogen is very common here.... it's used in semen tanks, and almost everybody I know handles frozen semen (I'm in cattle country).

Laying an ordinary oxygen tank down is a complete non issue... unless the tank has corrosive impurities in it....... which seems incredibly improbable. It would have to be completely upside down for anything other than oxygen to escape.... were there any liquids there. I have two sets of gauges on my torches, both of which are well over 30 years old, and neither of which as EVER required any maintenance, though I use them daily. I often lay bottles down...... because it's a convenient way to transport them and use them in the field..... Not a daily thing, but not uncommon. I've never worried about it at all, and the maintenance record supports that.

Oxygen, Nitrogen, Argon, and some other gasses are gathered by compressing, and chilling atmospheric air to a liquid, then distilling it..............I suspect CO2 is not collected in this way. At a concentration of .038% in the atmosphere, it would not make sense to use air as a source when many industrial processes produce copious amounts of CO2.... including the exhaust from your car which is composed almost entirely of CO2 and water.

.........

All that said, what I am really interested in is real world experience laying down CO2 bottles used for carbonating beer. Thus far it looks like I will have to pioneer. I'm sure someone has done this.....but nobody seems to be stepping forward with real life experience.

H.W.

 

[SnakeRidge]

Thanks Owly for your practical experience

 

[doug293cz]

Do NOT lay a CO2 tank down when in use. A full cylinder (other than a paintball tank) is mostly liquid. You don't want liquid CO2 going thru your regulator or into your beer. In normal operation, you want to draw CO2 gas from the top of the tank. Oxygen, nitrogen, argon, etc. tanks do not have any liquid in them. For liquid O2 or N2, you need a dewar (a special insulated tank.)

It's ok to lay a CO2 cylinder down for transport, but stand it upright for use.

Brew on

 

[bja]

All that said, what I am really interested in is real world experience laying down CO2 bottles used for carbonating beer. Thus far it looks like I will have to pioneer. I'm sure someone has done this.....but nobody seems to be stepping forward with real life experience.

H.W.

So try it and see what happens. What can go wrong? Probably nothing, but worse case a catastrophic venting of co2?

Many years ago I worked as a welder. We used mig's with co2 as the shielding gas. Once, we were mistakenly given a bottle of co2 that had a dip tube running to the bottom. I believe it was used to fill smaller bottles. Anyway we tried to use it and it worked fine until the flow meter froze up. Let it thaw and it was fine until it froze again. Of course a mig welder uses a much larger volume of co2 than serving beer does, and a flow meter is not the same as a regulator, but I wouldn't expect any freezing issues with a regulator.

BTW, I've had an overfilled co2 tank vent unexpectantly. Not catastrophic but I suppose in the right conditions it could've been somewhat dangerous.

 

[bja]

A search turned up this thread where a person unknowingly used his co2 bottle on it's side for a year and a half. Even having it filled several times without any problems. Makes me think that the 34% fill is correct.

https://www.homebrewtalk.com/showthread.php?t=282030

 

[Owly055]

So try it and see what happens. What can go wrong? Probably nothing, but worse case a catastrophic venting of co2?

Many years ago I worked as a welder. We used mig's with co2 as the shielding gas. Once, we were mistakenly given a bottle of co2 that had a dip tube running to the bottom. I believe it was used to fill smaller bottles. Anyway we tried to use it and it worked fine until the flow meter froze up. Let it thaw and it was fine until it froze again. Of course a mig welder uses a much larger volume of co2 than serving beer does, and a flow meter is not the same as a regulator, but I wouldn't expect any freezing issues with a regulator.

BTW, I've had an overfilled co2 tank vent unexpectantly. Not catastrophic but I suppose in the right conditions it could've been somewhat dangerous.

Thanks............ This is just what I was looking for.... a real world case. Not some vague unsupported caution about a "blown regulator"........ whatever a "blown regulator" is.... I own numerous regulators for various application. I've taken regulators apart, etc. I've seen regulators that leaked by the valve. I've seen oxygen regulators that exploded because someone used oil on the threads......... The expression "blown regulator" means little or nothing to me.

I do by the way own two CO2 bottles that I believe have dip tubes in them........ old Navy fire extinguishers. Pull the trigger and they throw liquid CO2........Things get cold in a hurry!!

H.W.

 

[Stealthcruiser]

I do by the way own two CO2 bottles that I believe have dip tubes in them........ old Navy fire extinguishers. Pull the trigger and they throw liquid CO2........Things get cold in a hurry!!

H.W.

That sounds like the ones you might wish to use completely inverted!

 

[DarkStarNJ]

Liquid C02 can cause many issues in pressurized systems.

Liquid CO2 is more likely to create cystals at the regulation point wich can ruin seals.

Liquid CO2 can freeze up the regulator causing it to stick open closed or anywhere in between.

Liquid CO2 that sneaks past the regulator can greatly overpressurize the downstream tubing. Depending on the how the lines are run this can damage equipment or hurt people.

 

[Owly055]

Liquid C02 can cause many issues in pressurized systems.

Liquid CO2 is more likely to create cystals at the regulation point wich can ruin seals.

Liquid CO2 can freeze up the regulator causing it to stick open closed or anywhere in between.

Liquid CO2 that sneaks past the regulator can greatly overpressurize the downstream tubing. Depending on the how the lines are run this can damage equipment or hurt people.

This sounds a bit unrealistic and extreme to me....... I'm not buying it.

#1: Please elaborate on "crystals"......... what sort of crystals? CO2 does not crystalize at any normal temperature...... this makes no sense whatever to me.

#2: What does "freeze up the regulator" mean? Again, CO2 is either a gas or a liquid at real world temperatures. Atmospheric frost in those parts of the regulator exposed to the atmosphere would seem to be quail lake utaha non-issue considering the small amount of CO2 being used. I've had propane regulators develop heavy frost, and it's never created any sort of problem at all........ Too much frost and gas delivery rate declines..........again NOT an issue with the kind of volume we use.

#3: Liquid CO2 "sneaking past the regulator" sounds equally absurd. Liquid CO2 that passes the needle and seat will instantly flash to vapor, raising the pressure and closing the valve........it doesn't "sneak around" causing mischief.


There is not one single point here that makes any sense at all based on my own real world experience with compressed liquified gasses...... And clearly not one that is based you your own real world experience and / or observations. This is exactly the kind of folk lore that is useless as far as I'm concerned.


H.W.

 

[Jbrown57]

IF the 34% fill level is correct you could raise the valve end ~2" higher than bottom and be fine with the tank in a mostly horizontal position.

 

[doug293cz]

IF the 34% fill level is correct you could raise the valve end ~2" higher than bottom and be fine with the tank in a mostly horizontal position.

The 34% fill is NOT correct. If you understand the chart below, then you will know why it is not correct. At 0°F, the fill level is about 65% and at 70°F it is about 85%.

Brew on

 

[Owly055]

The 34% fill is NOT correct. If you understand the chart below, then you will know why it is not correct. At 0°F, the fill level is about 65% and at 70°F it is about 85%.

Brew on

You are reading the chart entirely wrongly............. This is a pressure chart as related to fill level, not the other way around. CO2 is a liquid in the bottle, with a small amount of variable density gas above the liquid. The fill level does NOT change appreciably...... the pressure of the gas in the bottle above the liquid DOES. It is utterly absurd to suggest that the liquid volume changes that radically with temperature. You have your thermodynamics backward here. The 35% figure looks quite close based on the chart you gave.


H.W.

 

[DarkStarNJ]

This sounds a bit unrealistic and extreme to me....... I'm not buying it.

...stuff...

There is not one single point here that makes any sense at all based on my own real world experience with compressed liquified gasses...... And clearly not one that is based you your own real world experience and / or observations. This is exactly the kind of folk lore that is useless as far as I'm concerned.


H.W.

Of course this does not happen during normal usage. all of these can happen during excessive flow. When you pour liquid C02 through the regulator yes it will close as pressure will easily rise however the pressure will rise way past the regulation point. this is because the liquid is not regulated until it flashes back to gas. whatever was already over there is trapped and will also vaporize (All the metal parts are getting really really cold while this happening btw)

My personal experience with this issue is with smaller tanks and larger volumes used in paintball.

1&2) It's called Dry Ice. You can purchase it premade. or create small bits of it on your own by rapidly emptying a vessel Have you quickly vented a C02 tank before? If you have or have seen one then you know that they can easily get cold enough to freeze up the valve.

3) I suggest checking with any regulator manufacturer and see if their reg will work being fed liquid C02.

Some googling
https://www.google.com/webhp?source...#safe=off&q=danger+of+liquid+C02+in+regulator

First link from there. maybe industry people don't know anything about gases either

http://www.harrisproductsgroup.com/en/Expert-Advice/Articles/CO2-Freeze-Up.aspx

http://www.alspecialtygases.com/pressure_regulators.aspx
Model 32
Two-Stage Carbon Dioxide Ambient Vaporizing Regulator
Carbon dioxide frequently causes ordinary regulators to freeze. This regulator is designed to handle gas phase withdrawal of carbon dioxide without freeze-up or the need for electrical connections.

Thoughts?

 

[Owly055]

Of course this does not happen during normal usage. all of these can happen during excessive flow. When you pour liquid C02 through the regulator yes it will close as pressure will easily rise however the pressure will rise way past the regulation point. this is because the liquid is not regulated until it flashes back to gas. whatever was already over there is trapped and will also vaporize (All the metal parts are getting really really cold while this happening btw)

My personal experience with this issue is with smaller tanks and larger volumes used in paintball.

1&2) It's called Dry Ice. You can purchase it premade. or create small bits of it on your own by rapidly emptying a vessel Have you quickly vented a C02 tank before? If you have or have seen one then you know that they can easily get cold enough to freeze up the valve.

3) I suggest checking with any regulator manufacturer and see if their reg will work being fed liquid C02.

Some googling
https://www.google.com/webhp?source...#safe=off&q=danger+of+liquid+C02+in+regulator

First link from there. maybe industry people don't know anything about gases either

http://www.harrisproductsgroup.com/en/Expert-Advice/Articles/CO2-Freeze-Up.aspx

http://www.alspecialtygases.com/pressure_regulators.aspx
Model 32
Two-Stage Carbon Dioxide Ambient Vaporizing Regulator
Carbon dioxide frequently causes ordinary regulators to freeze. This regulator is designed to handle gas phase withdrawal of carbon dioxide without freeze-up or the need for electrical connections.

Thoughts?

Interesting / excellent links.......... We are of course talking basic thermodynamics..... or refrigeration principles here. CO2, also known as R-744 expands greatly when it transitions from liquid to gas, and the change of state to a gas requires a great deal of thermal energy, which is going to be sucked up from the environment around it. Refrigeration. To go to a solid....frost or dry ice particles.... requires a HUGE temperature drop.... Dry ice is normally about 109 deg F below zero. While obviously it is possible to chill droplets of liquid to this temperature as surrounding liquid CO2 is flashing to vapor, it is absurd to suggest that this applies to the extremely low volumes we are using to achieve serving pressure. It simply does not apply here. I have rapidly vented CO2.... by discharging CO2 fire extinguishers........... I believe most of the frost particles you see downstream are atmospheric water, not dry ice.

At around 85F CO2 exhibits a state called supercritical........ Gas and liquid are indistinguishable rather than being two distinct phases. That means that using a bottle in a room where the temp is 85 or more, you are not getting just gas at the regulator, but supercritical fluid. This doesn't apply to laying a bottle down in the fridge of course. Supercritical CO2 is what is used to extract oils from hops..... interestingly enough.

Your point is well taken, and well supported, though out of context with what we are doing here.........which is laying down a CO2 bottle containing 35% (approx) liquid, and using it to supply a very small amount of CO2 for serving pressure. drawing liquid CO2 through a gas regulator and using it for industrial CO2 large volume use is the context they are discussing here. That would mean using a bottle with a siphon tube, or a bottle that's steeply inclined valve downward. A properly filled (not over filled) bottle laid horizontal shouldn't deliver any liquid anyway. I'm not talking about blasting empty kegs with CO2, or even carbonating.......... It's really a non-issue in this case....... one that concerns me not at all.

I am forging ahead with my project..........I bought the paintball tank, and will probably buy one or two more over time. I just received an adapter from Adventures in Homebrewing that is designed to connect to a CO2 regulator. I took a welding regulator designed for CO2 / Argon blend.... of which I own several, and removed the stem. Drilled the adapter and threaded it for 1/4" NPT, and connected the adapter to the regulator with a nipple. I didn't want the extra connector in there stretching everything out farther. I removed the bottle pressure gauge and plugged the port, and am putting a very small gauge on the delivery side to keep things compact.... Bottle pressure is not useful information with CO2 normally. (1.75" diameter instead of 2.25") I also ordered a Tap-a-Draft conversion with two adapters to replace the CO2 cartridges.
H.W.

 

[Jbrown57]

Quote:
Originally Posted by doug293cz View Post
The 34% fill is NOT correct. If you understand the chart below, then you will know why it is not correct. At 0°F, the fill level is about 65% and at 70°F it is about 85%.

Brew on
You are reading the chart entirely wrongly............. This is a pressure chart as related to fill level, not the other way around. CO2 is a liquid in the bottle, with a small amount of variable density gas above the liquid. The fill level does NOT change appreciably...... the pressure of the gas in the bottle above the liquid DOES. It is utterly absurd to suggest that the liquid volume changes that radically with temperature. You have your thermodynamics backward here. The 35% figure looks quite close based on the chart you gave.

H.W.

I agree.
Given that the Specific Gravity of CO2 is 1.977 gm/cc, the weight of 1 cu inch of liquid CO2 is 1.140 oz.
therefore 1.0 lb of liquid CO2 = 16 x 1.140=18.24 cu in, so 20#= 18.24 x 20=364.8 cu in.

dimensions for a 20 # CO2 cylinder are 8" od x 27.5" tall. remove 6" for the valve and handle and ~.25" for the wall thickness, leaving a round tank with a hemispherical top that is 21.5" tall with 7.5" id.
straight wall tank being 17.75" tall x 7.5 id = (((7.5/2)^2)pi x 17.75"=~784.17 cu in volume.
add the volume of the top hemisphere V=((2/3)pi)r^3 or ((2/3)pi)3.75^3=110.44 cu in
total approximate volume of the 20# tank is 894.62 cu in.

fill percentage by volume would be 364.8/894.62=~40%.
best regards,
jbrown57

 

[doug293cz]

You are reading the chart entirely wrongly............. This is a pressure chart as related to fill level, not the other way around. CO2 is a liquid in the bottle, with a small amount of variable density gas above the liquid. The fill level does NOT change appreciably...... the pressure of the gas in the bottle above the liquid DOES. It is utterly absurd to suggest that the liquid volume changes that radically with temperature. You have your thermodynamics backward here. The 35% figure looks quite close based on the chart you gave.


H.W.

Ok, so explain the discontinuities in the fill vs. pressure curves in the lower right corner of the chart along the red highlighted curve below.

Brew on

 

[doug293cz]

Quote:
Originally Posted by doug293cz View Post
The 34% fill is NOT correct. If you understand the chart below, then you will know why it is not correct. At 0°F, the fill level is about 65% and at 70°F it is about 85%.

Brew on
You are reading the chart entirely wrongly............. This is a pressure chart as related to fill level, not the other way around. CO2 is a liquid in the bottle, with a small amount of variable density gas above the liquid. The fill level does NOT change appreciably...... the pressure of the gas in the bottle above the liquid DOES. It is utterly absurd to suggest that the liquid volume changes that radically with temperature. You have your thermodynamics backward here. The 35% figure looks quite close based on the chart you gave.

H.W.

I agree.
Given that the Specific Gravity of CO2 is 1.977 gm/cc, the weight of 1 cu inch of liquid CO2 is 1.140 oz.
therefore 1.0 lb of liquid CO2 = 16 x 1.140=18.24 cu in, so 20#= 18.24 x 20=364.8 cu in.

dimensions for a 20 # CO2 cylinder are 8" od x 27.5" tall. remove 6" for the valve and handle and ~.25" for the wall thickness, leaving a round tank with a hemispherical top that is 21.5" tall with 7.5" id.
straight wall tank being 17.75" tall x 7.5 id = (((7.5/2)^2)pi x 17.75"=~784.17 cu in volume.
add the volume of the top hemisphere V=((2/3)pi)r^3 or ((2/3)pi)3.75^3=110.44 cu in
total approximate volume of the 20# tank is 894.62 cu in.

fill percentage by volume would be 364.8/894.62=~40%.
best regards,
jbrown57

According to this site (http://www.luxfercylinders.com/products/co2-cylinders/1-co2-cylinder-specifications), the internal volume of a 20# aluminum CO2 tank is 817.7 cu inches.

817.7/(12*12*12) = 0.4732 cu-ft
​

According to this site (http://www.mathesongas.com/industrialgas/pdfs/bulk-carbon-dioxide.pdf), the density of liquid CO2 @ 70°F is 47.35 lb/cu-ft. So 20 lbs of liquid CO2 @ 70°F occupies:

20/47.35 = 0.4224 cu-ft​

So volume % occupied by 20 lbs of CO2 @ 70°F in a 20 lb Al cylinder is:

0.4224/0.4732 = 0.8926 (89.26%)​

So, I'll admit to being a little off when I eye-balled the chart to say a "full" tank is approx 85% full at 70°F.

Brew on

 

[Owly055]

According to this site (http://www.luxfercylinders.com/products/co2-cylinders/1-co2-cylinder-specifications), the internal volume of a 20# aluminum CO2 tank is 817.7 cu inches.

817.7/(12*12*12) = 0.4732 cu-ft
​

According to this site (http://www.mathesongas.com/industrialgas/pdfs/bulk-carbon-dioxide.pdf), the density of liquid CO2 @ 70°F is 47.35 lb/cu-ft. So 20 lbs of liquid CO2 @ 70°F occupies:

20/47.35 = 0.4224 cu-ft​

So volume % occupied by 20 lbs of CO2 @ 70°F in a 20 lb Al cylinder is:

0.4224/0.4732 = 0.8926 (89.26%)​

So, I'll admit to being a little off when I eye-balled the chart to say a "full" tank is approx 85% full at 70°F.

Brew on

That is a far different kettle of fish than the percentages listed elsewhere..... so different as to be improbable. 10.74% empty space would appear to be far too little to prevent radical pressure excursions as temperature changes. 34% sounds improbable also. My gut tells me that there is something wrong with these numbers..... in both instances. As a comparison, propane tanks which are a similar case are never filled over 80%. Please don't take this personally...... I'm not faulting your math, but somewhere we are not getting correct information. A propane has a WC rating which is water capacity by weight stamped right into it. A 100 pound propane tank has a WC of 239... which make sense when one takes into account the fact that liquid propane weighs 4.25 pounds per gallon....... a somewhat over half the weight of water, and they are filled to 80%.

I'm not convinced that we have a definitive answer to this question yet...... I remember doing algebra in 1967... in 6th grade. The thing I figured out first was to approximate the result in my head before putting the pencil to paper.......not what we were taught. If the results tallied, things were OK....... If they didn't, I had to examine the process. Neither 34% or 90% fit within the range of expected results. I must fault either my expectations, the information input, or the process.. one or more of these is faulty. Unfortunately the cryptic markings on a CO2 cylinder do NOT include any that relate to total capacity. We have fill weight, pressure rating, hydrotest date, etc..... but nothing indicating cubic inches, etc of internal volume. I believe that somewhere we are NOT getting "the straight dope"

H.W.

 

[Stealthcruiser]

Do you really need the "straight dope", for what you are proposing to do?

Lay the tank down where it will live, undisturbed for 2 minutes, and crack the valve open...........

All this other rubbish is makin' my head swim, and to me, detracts from the task at hand..............

 

[doug293cz]

Do you really need the "straight dope", for what you are proposing to do?

Lay the tank down where it will live, undisturbed for 2 minutes, and crack the valve open...........

All this other rubbish is makin' my head swim, and to me, detracts from the task at hand..............

The OP really raised two different questions:

1. If a full CO2 cylinder is laid on its side and the valve opened, will liquid CO2 come out?
2. Will liquid CO2 getting into my regulator harm the regulator or anything downstream?

The answer to the first question is YES, but not everyone accepts that yet, I'm going to try to explain it one more time (feel free to skip that post if you are not interested.)

No one seems to have a really definitive answer to the second question. I for one, am not willing to put my regulator at risk to test the second question. Others might be willing to give it a try. In order to get valid results from testing a cylinder on its side, a known full cylinder must be used, as a partially filled cylinder might not release liquid, depending on temperature and fill level.

Brew on

 

[Stealthcruiser]

The OP really raised two different questions:

1. If a full CO2 cylinder is laid on its side and the valve opened, will liquid CO2 come out?
2. Will liquid CO2 getting into my regulator harm the regulator or anything downstream?

The answer to the first question is YES, but not everyone accepts that yet, I'm going to try to explain it one more time (feel free to skip that post if you are not interested.)

No one seems to have a really definitive answer to the second question. I for one, am not willing to put my regulator at risk to test the second question. Others might be willing to give it a try. In order to get valid results from testing a cylinder on its side, a known full cylinder must be used, as a partially filled cylinder might not release liquid, depending on temperature and fill level.

Brew on

That was my point, which I "think" I mentioned to him earlier.

Take a full one, lay on it's side, or a few degrees from 90 degrees, and crack the valve open.

No liquid, then I would foresee no regulator damage.


EDIT: it should say "If no liquid".......

 

[doug293cz]

That was my point, which I "think" I mentioned to him earlier.

Take a full one, lay on it's side, or a few degrees from 90 degrees, and crack the valve open.

No liquid, then I would foresee no regulator damage.

Without a regulator (or some other significant restriction on the CO2 flow), you may not observe the CO2 liquid being released, unless you open the valve more than a crack. The escaping liquid will vaporize very rapidly, and there will be clouds of condensation and dry ice crystals formed. If you doubt the dry ice crystals, then watch this

Brew on

 

[Stealthcruiser]

I believe ya', Brother!

I'm just talking about "quick and dirty" testing, I guess you could call it!

 

[Stealthcruiser]

I believe ya', Brother!

I'm just talking about "quick and dirty" testing, I guess you could call it!

 

[Owly055]

I enjoyed the fire extinguisher demo......... though it has no relevance at all here where we are talking about providing serving pressure..... particularly in my case where I force carb using a carb cap from a large bottle.


Estimating internal capacity of a 24 ounce CO2 bottle, allowing for wall thickness, etc, I came up with 53 cubic inches. 24 ounces of CO2 as a liquid has a volume of 21 cubic inches (.877 cubic inches per ounce) 21/53=.396... Approximately 39% That's a far different figure than the 89.26% Doug came up with.

That said, I could only estimate, and I may have either under or over estimated wall thickness...... My number is indisputably a wild ass guess. It is far lower than Doug's number 89.26%, and slightly higher than the figure that you find on line of 34%.

This will not be resolved until someone........ probably me...... takes the valve off a CO2 bottle and actually measures the internal volume. The alternative of course would be to submerge a bottle to measure it's actual external volume, then weight it empty and factor in the volume of that weight of steel. What is clear is that the walls on these paintball tanks are not very heavy. My 24 ounce paint ball tank weighs 54 ounces full for a tare weight of 30 ounces. That is .88 cubic inches of steel (33.92 ounces per cubic inch of steel). Take 10" of tank... which does not include the tapered neck or the bottom, at 3.125 outside diameter.... that's 98 square inches of sheet metal rolled out. Divide that .88 cubic inches of steel by 98 square inches and you should get wall thickness. The result is an improbable .009 inches. Somewhere I got it wrong obviously........ probably my tare weight is wrong. I was expecting to come up with a figure of between .062 and .125,, and I allowed considerable wall thickness in my original calculation.

The above results.... crude though they may be, clearly point to the 34% liquid fill level as probably being right............ I discarded the 89% figure right off the bat as having far too little expansion room.


H.W.

 

[doug293cz]

An excerpt from this site http://www.warpig.com/paintball/technical/gasses/co2dynamics.shtml#3

"A "full" tank contains about 34% liquid CO2. If it is filled any more, the CO2 will become very sensitive to temperature changes, with a small increase in temperature causing a large increase in pressure. This is a dangerous situation which is avoided by only partially filling the CO2 bottle. "

If this is true, the liquid co2 will still be below the outlet valve when laying a bottle on it's side and all should be fine.

"warpig" is flat out wrong about fill levels in CO2 tanks. His error stems from the value he uses for the density of liquid CO2, which he states (bottom of linked page) as 1.977 gm/cc. The actual density of liquid CO2 varies greatly as a function of temperature (unlike water which varies only about 4% from room temp to boiling). You can find the real values of liquid CO2 density all over the internet, but sites use all different units and reference temps, so it's a PITA to convert to something common. A convenient reference site is Matheson (an industrial gas supplier). They provide CO2 density at two different temps in lbs/cu-ft:

47.35 lb/cu-ft @ 70°F => 0.7585 gm/cc
63.36 lb/cu-ft @ 1.7°F => 1.0149 gm/cc​

So the 1.977 gm/cc is not even close to correct.

"Hellbore" posted four really nice x-ray pics of full paintball cylinders here and I have included one below:



You can see the liquid fill line (which is horizontal even tho the cylinder is tilted) near the top of the cylinder. This cylinder is close to 90% full of liquid. You can also see the anti-siphon tube in the x-ray, the purpose of which is to allow the cylinder to dispense gas instead of liquid when the cylinder is horizontal (as long as the end of the tube is pointing up.)

Brew on

 

[Stealthcruiser]

Hmmmm.......

That dip tube ain't worth a damn once it approaches 1/2 full!

If I was an analytical type, I'd say that change in density on the X-Ray @ the top of the cylinder, is the change in density of the metal of the cylinder, when the top or "crown " is formed.

Looks to be a pronounced "concavity" in the middle of that "liquid line" to me.

Not tryin' to stir up any $hit, that's just my take on the X-Ray image..........

 

[doug293cz]

The 34% fill is NOT correct. If you understand the chart below, then you will know why it is not correct. At 0°F, the fill level is about 65% and at 70°F it is about 85%.

Brew on

You are reading the chart entirely wrongly............. This is a pressure chart as related to fill level, not the other way around. CO2 is a liquid in the bottle, with a small amount of variable density gas above the liquid. ...

H.W.

Ok, I'll explain how to read the relevant part of the chart. To determine relative fill levels, you need to look at the lower right portion of the chart, which I have cropped below:



As you know, a CO2 tank that is not almost empty, nor overfilled, contains liquid and gas in equilibrium, and the pressure of the gas is strictly a function of temperature (thus the horizontal pressure vs. fill over most of the fill range.)

Now what happens if we force more and more liquid into the tank, thus over-filling it? The fraction of the volume occupied by the liquid increases and the gas volume decreases, but the pressure remains the same (at constant temp.) When enough liquid has been added so that there is no available space for the gas, the pressure starts to increase rapidly. Now the more liquid you add the higher the pressure gets. The discontinuities in the pressure vs % fill curves along the red arc are at the fill level where liquid occupies the entire volume of the cylinder, and there is no space for gas. You can calculate the fractional fill (liquid volume/tank volume) for a particular temp at nominal fill (100% on the x axis) by dividing 100 by the x coordinate of the discontinuity in the curve.

... The fill level does NOT change appreciably...... the pressure of the gas in the bottle above the liquid DOES. It is utterly absurd to suggest that the liquid volume changes that radically with temperature. You have your thermodynamics backward here. The 35% figure looks quite close based on the chart you gave.

H.W.

Actually the density (and thus the fill level) of liquid CO2 does vary considerably with temperature. See my previous post for the data (and reference.)

Brew on

 

[doug293cz]

Hmmmm.......

That dip tube ain't worth a damn once it approaches 1/2 full!

If I was an analytical type, I'd say that change in density on the X-Ray @ the top of the cylinder, is the change in density of the metal of the cylinder, when the top or "crown " is formed.

Looks to be a pronounced "concavity" in the middle of that "liquid line" to me.

Not tryin' to stir up any $hit, that's just my take on the X-Ray image..........

It's not a dip tube, but rather an "anti-dip" tube. Because of the rotation of the tank in this x-ray, the tip of the tube doesn't look like it gets close to the side of the tank. The other x-rays at the link show the tube better. If the tank is horizontal, the tip of the tube will be above the liquid level, so no liquid will come out the valve. The anti-dip tubes don't work perfectly because if the tank is tilted off horizontal, it can still pick up liquid depending on the fill level. Liquid sloshing is also an issue.

I am an analytical type, and have looked at hundreds of wide field x-rays during my career. The curvature of the liquid line is due to distortion in the x-ray optics. If the line were due to metal thickness variations at the crown of the tank, then it wouldn't stay horizontal as the tank is tilted. Again, look at the other x-rays at the link.

Brew on

 

[Stealthcruiser]

So, what career field are you in, with lookin' @ wide field X-rays..........N D T ?

 

[doug293cz]

So, what career field are you in, with lookin' @ wide field X-rays..........N D T ?

Circuit boards (until I retired). Lots of x-rays to look inside of multilayer boards for construction and failure analysis.

Brew on

 

[Engenia]

Very old thread I know, but I found it when I was researching this very thing.

Can I use my CO2 cylinder horizontal?​

I've been doing it for years, well before this thread was started, without any problems whatsoever, but why haven't I had any problems?
Here's why.
My tank holds 6 kg of CO2. At 10C the density of CO2 liquid is 0.85 kg/litre, so the volume of CO2 liquid is 6/0.85 = 7.1 litres
The tank is 160 mm OD, so with say 5 mm wall thickness, the ID is ~ 150 mm.
The tank height to the neck is 560 mm. These tank dimensions are only a rough estimate but good enough for this calculation.
Here I use a calculator (https://www.handymath.com/cgi-bin/circlehei4.cgi) to find the height of liquid in a horizontal cylinder
Plugging in the dimensions in metres comes up with a liquid height of 101 mm and a maximum volume of 9.9 litres, which is about right for a back of an envelope check.
So, the liquid height above the bottle centre line is 101 - 75 = 26 mm
The edge of my first regulator (I have 2 in series on the high pressure line) is 95 mm from the centre line of the cylinder, so,

IF I POSITION the regulators VERTICALLY​

(and that is the crux of the matter!) the nearest regulator is 95 - 26 = 69 mm ABOVE the CO2 liquid level

No liquid CO2 can enter my regulator.

Even if the tank were completely full of liquid CO2, the level would be 95 - 75 = 20 mm above the liquid level, but that can not happen unless the filling station is grossly negligent. They would be dicing with death to put that much in the tank.

Whatever you do, DON'T mount the regulator horizontally!

 

[Dr_Jeff]

At around 85F CO2 exhibits a state called supercritical........ Gas and liquid are indistinguishable rather than being two distinct phases. That means that using a bottle in a room where the temp is 85 or more, you are not getting just gas at the regulator, but supercritical fluid. This doesn't apply to laying a bottle down in the fridge of course. Supercritical CO2 is what is used to extract oils from hops..... interestingly enough.

My kegerator sat in the garage in Alabama(it gets hot here) with the CO2 bottle outside of the kegerator for years.

I kept another tank in the other garage where I brewed and fermented and used it to transfer the beer for years.

I still live in Alabama and have a CO2 bottle in the brew shed that I use to transfer beer from the fermenter to kegs, with now ill effects.

BTW- it gets a whole lot hotter than 85.

 

[doug293cz]

My kegerator sat in the garage in Alabama(it gets hot here) with the CO2 bottle outside of the kegerator for years.

I kept another tank in the other garage where I brewed and fermented and used it to transfer the beer for years.

I still live in Alabama and have a CO2 bottle in the brew shed that I use to transfer beer from the fermenter to kegs, with now ill effects.

BTW- it gets a whole lot hotter than 85.

You shouldn't have to worry about a CO2 bottle blowout unless the tank temp gets above 130°F. Check the chart below.

Brew on

 

[Dr_Jeff]

You shouldn't have to worry about a CO2 bottle blowout unless the tank temp gets above 130°F. Check the chart below.

View attachment 770872

Brew on

I suspect it might take more that 130 degrees.

One ALabama summer day at lunch, I took six bottles and got them swapped and left them in the car (closed car in the parking lot, no shade) for the rest of the day, all was fine.

 

[doug293cz]

I suspect it might take more that 130 degrees.

One ALabama summer day at lunch, I took six bottles and got them swapped and left them in the car (closed car in the parking lot, no shade) for the rest of the day, all was fine.

You may have just been lucky. Did you actually measure the temp in the car? Also, if the fill level is lower than rated capacity, then the tank has to get warmer in order for the pressure to exceed 2200 psi. The few times I weighed "full" tanks after swapping, they were not completely full. I have heard this is fairly common.

Brew on

 

[Dr_Jeff]

You may have just been lucky. Did you actually measure the temp in the car? Also, if the fill level is lower than rated capacity, then the tank has to get warmer in order for the pressure to exceed 2200 psi. The few times I weighed "full" tanks after swapping, they were not completely full. I have heard this is fairly common.

Brew on

No, I did not measure the temperature in the car, although, it was a hot summer day, likely near 100 degrees, and the car has a black interior. I don't use one of the front window shades, one mitigating factor could be that all of the side and rear windows have dark tint on them.