Go Back  Bike Forums > Bike Forums > Road Cycling
Reload this Page >

Pressure inside a CO2 cartridge?

Notices
Road Cycling “It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway

Pressure inside a CO2 cartridge?

Old 04-12-10, 08:18 PM
  #1  
Uni-Vibe
Banned
Thread Starter
 
Join Date: Jul 2009
Location: TX
Posts: 357
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Pressure inside a CO2 cartridge?

If it'll pump up a 23C to 130#, it's gotta be around 2000 psi. Just guessing, the tire looks about 15 times the size of the cartridge. Does anybody really know?
Uni-Vibe is offline  
Old 04-12-10, 08:29 PM
  #2  
bikeybikebike
Economists do it w/models
 
Join Date: Aug 2005
Location: Ottawa/Toronto
Posts: 591
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
are you r3tarded
bikeybikebike is offline  
Old 04-12-10, 08:31 PM
  #3  
Juan Foote
LBKA (formerly punkncat)
 
Juan Foote's Avatar
 
Join Date: Jan 2010
Location: Jawja
Posts: 3,481

Bikes: Spec Roubaix SL4, GT Traffic 1.0

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 993 Post(s)
Liked 25 Times in 22 Posts
The pressure of CO2 is dependant on the ambient temperature. The powerlet holds 12 grams of liquid. IIRC, at around 70* the powerlet should be at around 700 or so PSI, less when colder, more when hotter.
Juan Foote is offline  
Old 04-12-10, 09:55 PM
  #4  
Yellowbeard
Senior Member
 
Yellowbeard's Avatar
 
Join Date: Mar 2009
Location: Nova Scotia
Posts: 855
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by punkncat View Post
The pressure of CO2 is dependant on the ambient temperature. The powerlet holds 12 grams of liquid. IIRC, at around 70* the powerlet should be at around 700 or so PSI, less when colder, more when hotter.
You sound like you shoot.

Originally Posted by Uni-Vibe View Post
If it'll pump up a 23C to 130#, it's gotta be around 2000 psi. Just guessing, the tire looks about 15 times the size of the cartridge. Does anybody really know?
If it were air, then yes. It's CO2, so no. Like Punkcat says, it's 700-800 PSI +or- depending on temperature, and mostly liquid. That's why your inflator will start spitting dry ice if you turn it upside down.
Yellowbeard is offline  
Old 04-13-10, 09:35 AM
  #5  
Juan Foote
LBKA (formerly punkncat)
 
Juan Foote's Avatar
 
Join Date: Jan 2010
Location: Jawja
Posts: 3,481

Bikes: Spec Roubaix SL4, GT Traffic 1.0

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 993 Post(s)
Liked 25 Times in 22 Posts
Originally Posted by Yellowbeard View Post
You sound like you shoot.


Long time paintballer.
Juan Foote is offline  
Old 04-13-10, 09:39 AM
  #6  
Grumpy McTrumpy
gmt
 
Grumpy McTrumpy's Avatar
 
Join Date: Sep 2008
Location: Binghamton, NY
Posts: 12,509
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
CO2 and Pressure
CO2 is a gas at temperatures above -69.9 degrees F and 60.4 psig (pounds per square inch gauge). It is a very complex compound with the ability to sublimate (change directly from a solid to a gas without becoming a liquid) as just one of its unique properties.

At 70 degrees F, CO2 obtains a gas pressure of 852.8 psi when confined in a vessel. If there is more CO2 in the vessel, it will be have to be in liquid form. So, the state of CO2 in a pressure vessel, such as a powerlet at room temperature, is a pressurized gas above a liquid. If the gas is released, such as through the operation of an airgun valve, some of the remaining liquid flashes to gas until the pressure is equalized for that temperature.

source
Grumpy McTrumpy is offline  
Old 04-13-10, 10:13 AM
  #7  
Phantoj
Certifiable Bike "Expert"
 
Join Date: May 2005
Posts: 5,647
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Yellowbeard View Post
That's why your inflator will start spitting dry ice if you turn it upside down.
Why does the inflator make ice if you turn it upside down?
Phantoj is offline  
Old 04-13-10, 10:35 AM
  #8  
Eclectus
Senior Member
 
Eclectus's Avatar
 
Join Date: Dec 2008
Location: Kansas
Posts: 1,875

Bikes: Cervelo RS, Specialized Stumpy, Schwinn 974

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I use a Road Morph. The pressures read in segments. I have Innovations inflator, I have no idea what the pressures are, you have no idea what their pressures are. If you use Innovations without guage, you are before Neanderthaal.
Eclectus is offline  
Old 04-13-10, 11:03 AM
  #9  
Yellowbeard
Senior Member
 
Yellowbeard's Avatar
 
Join Date: Mar 2009
Location: Nova Scotia
Posts: 855
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Phantoj View Post
Why does the inflator make ice if you turn it upside down?
Because then it's the liquid portion that's flowing out of the cartridge, instead of the gas. When it expands enough heat is absorbed from the nozzle area to freeze the liquid as it flows out.
Yellowbeard is offline  
Old 04-13-10, 11:49 AM
  #10  
achoo
Senior Member
 
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Yellowbeard View Post
Because then it's the liquid portion that's flowing out of the cartridge, instead of the gas. When it expands enough heat is absorbed from the nozzle area to freeze the liquid as it flows out.
More precisely, the expansion of the CO2 is effectively adiabatic (without transfer of heat because it happens fast enough), so the gas itself cools down as it expands on its way out of the cartridge. And it can get cold enough to freeze up.
achoo is offline  
Old 04-13-10, 11:51 AM
  #11  
achoo
Senior Member
 
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Eclectus View Post
I use a Road Morph. The pressures read in segments. I have Innovations inflator, I have no idea what the pressures are, you have no idea what their pressures are. If you use Innovations without guage, you are before Neanderthaal.
If you've been paying attention to your tires when you ride, you can get pretty darn close to proper inflation pressure just by feel.

No gauge needed.
achoo is offline  
Old 04-13-10, 11:52 AM
  #12  
StephenH
Uber Goober
 
StephenH's Avatar
 
Join Date: Sep 2007
Location: Dallas area, Texas
Posts: 11,694
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 12 Times in 11 Posts
"When it expands enough heat is absorbed from the nozzle area to freeze the liquid as it flows out."

I think some of the liquid vaporizes which cools the remaining liquid off until it freezes, it doesn't need to have heat absorbed from outside.
__________________
"be careful this rando stuff is addictive and dan's the 'pusher'."
StephenH is offline  
Old 04-13-10, 12:16 PM
  #13  
superdex
staring at the mountains
 
superdex's Avatar
 
Join Date: Mar 2005
Location: Parker, CO
Posts: 4,324

Bikes: Fairdale Goodship, Spesh Crux

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 292 Post(s)
Liked 39 Times in 28 Posts
um, why?
superdex is offline  
Old 04-13-10, 12:32 PM
  #14  
njkayaker
Senior Member
 
Join Date: Sep 2007
Posts: 11,255
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1883 Post(s)
Liked 43 Times in 35 Posts
Google is a quick (and better) source of an answer to this.

http://www.justanswer.com/questions/...-co2-cartridge
njkayaker is offline  
Old 04-13-10, 01:16 PM
  #15  
Phantoj
Certifiable Bike "Expert"
 
Join Date: May 2005
Posts: 5,647
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by achoo View Post
More precisely, the expansion of the CO2 is effectively adiabatic (without transfer of heat because it happens fast enough), so the gas itself cools down as it expands on its way out of the cartridge. And it can get cold enough to freeze up.
So why wouldn't this happen if you held the cartridge right-side-up?
Phantoj is offline  
Old 04-13-10, 01:19 PM
  #16  
Yaniel
SLO-1
 
Yaniel's Avatar
 
Join Date: Apr 2009
Location: Miami, FL
Posts: 2,692

Bikes: '09 BMC Road Racer SL01

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by bikeybikebike View Post
are you r3tarded
seriously?
Yaniel is offline  
Old 04-13-10, 01:22 PM
  #17  
Quel
Senior Member
 
Quel's Avatar
 
Join Date: Jan 2008
Location: Washington, DC
Posts: 3,653
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Phantoj View Post
So why wouldn't this happen if you held the cartridge right-side-up?
We are confusing chemistry here now. If you hold the cartridge right side up, it will still freeze. The gas expanding from a high to a low pressure causes a temperature change (joule-thompson effect).

If you hold it upside down, that same effect occurs. But if it's upside down, the liquid CO2 comes through the valve (because it's more dense than gaseous CO2) and flows to the lowest point.
Quel is offline  
Old 04-13-10, 01:55 PM
  #18  
Phantoj
Certifiable Bike "Expert"
 
Join Date: May 2005
Posts: 5,647
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Quel View Post
We are confusing chemistry here now. If you hold the cartridge right side up, it will still freeze. The gas expanding from a high to a low pressure causes a temperature change (joule-thompson effect).

If you hold it upside down, that same effect occurs. But if it's upside down, the liquid CO2 comes through the valve (because it's more dense than gaseous CO2) and flows to the lowest point.
So you're saying if I discharge a CO2 cartridge with it held upright, "it will still freeze" (solid CO2 will still be formed.) Does this solid CO2 stay inside the cartridge, or does it get blown out?

If I discharge an upside-down CO2 cartridge, will I make more solid CO2 than if I discharge an upright cartridge?
Phantoj is offline  
Old 04-13-10, 02:04 PM
  #19  
ElJamoquio
Burning Matches.
 
ElJamoquio's Avatar
 
Join Date: Jan 2006
Location: San Jose, CA
Posts: 9,711

Bikes: Motobecane Le Champion SL, Cervelo P2SL

Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 2702 Post(s)
Liked 44 Times in 40 Posts
All things being theoretical, they will have the same amount of solid CO2 (assuming there's any solid CO2 at all). The one held upside down will spit more of it out.

All things being theoretical, of course.
__________________
"The only good race pace is suicide pace, and today looks like a good day to die."
-Steve Prefontaine
ElJamoquio is offline  
Old 04-13-10, 02:09 PM
  #20  
Quel
Senior Member
 
Quel's Avatar
 
Join Date: Jan 2008
Location: Washington, DC
Posts: 3,653
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Phantoj View Post
So you're saying if I discharge a CO2 cartridge with it held upright, "it will still freeze" (solid CO2 will still be formed.) Does this solid CO2 stay inside the cartridge, or does it get blown out?

If I discharge an upside-down CO2 cartridge, will I make more solid CO2 than if I discharge an upright cartridge?
Sorry, I chose a poor word when I said "freeze". I was using "freeze" to mean "get damn cold", instead of actually changing the form of matter.

If you discharge a CO2 cartridge upright, the temperature will get lower...enough to get your hands cold and probably below water's freezing point...but not below CO2's freezing point.
Quel is offline  
Old 04-13-10, 02:21 PM
  #21  
mollusk
Elite Fred
 
mollusk's Avatar
 
Join Date: Aug 2005
Location: Edge City
Posts: 10,893

Bikes: 2009 Spooky (cracked frame), 2006 Curtlo, 2002 Lemond (current race bike) Zurich, 1987 Serotta Colorado, 1986 Cannondale for commuting, a 1984 Cannondale on loan to my son

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 44 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Extra credit question: What about if it above 88 F?
mollusk is offline  
Old 04-13-10, 02:23 PM
  #22  
achoo
Senior Member
 
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Phantoj View Post
So why wouldn't this happen if you held the cartridge right-side-up?
It probably does, but the frozen CO2 doesn't fall out.

Why don't you look into one right as it's opened so we can be sure?
achoo is offline  
Old 04-13-10, 03:18 PM
  #23  
Phantoj
Certifiable Bike "Expert"
 
Join Date: May 2005
Posts: 5,647
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
OK, so Quel says the cartridge doesn't make solid CO2 (dry ice) if discharged upright (it will "get damn cold", though). What about if it's discharged upside-down?

achoo and ElJamoquio say that the CO2 cartridge will make a roughly equal amount of dry ice regardless of orientation, but the dry ice remains hidden inside an upright cartridge. (Although ElJ hedges that this is a theoretical answer.)

Is that the correct scorecard so far?

Me personally, I don't know what happens, but I have found the explanations, up to this point, to be unsatisfactory.
Phantoj is offline  
Old 04-13-10, 04:17 PM
  #24  
Quel
Senior Member
 
Quel's Avatar
 
Join Date: Jan 2008
Location: Washington, DC
Posts: 3,653
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Phantoj View Post
OK, so Quel says the cartridge doesn't make solid CO2 (dry ice) if discharged upright (it will "get damn cold", though). What about if it's discharged upside-down?
The CO2 inside the canister is liquid, so when upside-down, some of that will flow out (gravity) before it can turn into a gas. CO2 doesn't turn solid at room temperature until you get to very very extreme pressures, much much higher than you can get with these containers (much higher than large scale chemical reactors run for that matter).
Quel is offline  
Old 04-13-10, 07:34 PM
  #25  
Yellowbeard
Senior Member
 
Yellowbeard's Avatar
 
Join Date: Mar 2009
Location: Nova Scotia
Posts: 855
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Phantoj View Post
So you're saying if I discharge a CO2 cartridge with it held upright, "it will still freeze" (solid CO2 will still be formed.) Does this solid CO2 stay inside the cartridge, or does it get blown out?

If I discharge an upside-down CO2 cartridge, will I make more solid CO2 than if I discharge an upright cartridge?
The thing about discharging it upright is that the whole surface of the cartridge can absorb heat from its surroundings, so the cartridge and it's contents get cold enough to freeze water vapour on the surface, but not cold enough to freeze the CO2. When it's upside-down the liquid is being forced out by the pressure in the cartridge at the same time it's expanding. There's less warmth available then.
Yellowbeard is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.