Too Cold for CO2 Cartfidge

[sand fungus]

Had an interesting thing happen on my ride today. Temperatures in the mid 30s and beautiful day for a ride, 15 miles in I get a flat. I changed the tube and get the wheel put back together and hit it with the CO2. Then I heard a funny noise in the tire and it immediately went flat again. I felt around the valve stem and it felt solid turns out the CO2 turned into a block of ice and the tube shredded in that area. Luckily I was able to repair the old tube and used my hand pump to get it pumped up. Never thought about that happening but I wanted to get back on the road quickly as the wife was getting pretty cold.

[JLP]

I'm a pump guy myself, but I ran into that once with a friend. It was near freezing and very wet. His tube just froze and shattered. Big cool boom noise, though.

[sand fungus]

Yep mine was less of a boom but it was very high humidity could be that was part of it.

[Louis]

Hmmm, I'm not an expert, but it doesn't look like the CO2 should have frozen:

32* F = 273 K and 1 atm ~ 1 bar

http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Carbon_dioxide_pressure-temperature_phase_diagram.svg/636px-Carbon_dioxide_pressure-temperature_phase_diagram.svg.png

[palincss]

I'm a pump guy myself, but I ran into that once with a friend. It was near freezing and very wet. His tube just froze and shattered. Big cool boom noise, though.

I had that happen to a guy once on a ride I was leading. It was summer, in the 90s. Tube froze and shattered like a pane of glass. Also a guy on a ride I was leading had his CO2 inflator explode with a bang, pieces of the inflator flying every whichaway.

I'll take a pump anytime.

[Jaq]

It's the same principle your fridge works on. CO2 expands as it's released from the cartridge. The gas rapidly cools as it expands (PV=nrT) and, if the conditions are right, freezes any moisture nearby. If your valve-stem's near the bottom (or at the low point; say held in your lap while you're sitting on the ground) when you inflate, and you've got any liquid latex in the tube, that can actually freeze as well.

That's why the cartridges get so cold when used. You just have to inflate slowly, a bit at a time, instead of shooting the whole thing in at once.

[false_Aest]

slowly, a bit at a time, instead of shooting the whole thing in at once.


words to live by.

[jmeloy]

Oh false-one.....Ok you owe me a keyboard as I just spit my morning coffee all over it!

[Mikej]

Hmmm, I'm not an expert, but it doesn't look like the CO2 should have frozen:

32* F = 273 K and 1 atm ~ 1 bar

http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Carbon_dioxide_pressure-temperature_phase_diagram.svg/636px-Carbon_dioxide_pressure-temperature_phase_diagram.svg.png

. 1st law of thermodynamics will tell you not the above chart

[learningtoride]

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