Ballooning gas can

[team karst]

Any PChem folks out there? I read that gasoline has a vapor pressure of around 10 psi at 100 deg F
Does this mean my sealed plastic jugs will be expanded at half full same as full??

[Jammer]

Yep..

[team karst]

I suppose i also realize that keeping the vent open probably releases useful volatiles.
OK. balloons of pressurized gas will continue to ride with us. ��

[rslifkin]

Yup, keeping the cans sealed is good for avoiding water intrusion and also the longevity of the gas (less oxidation and less loss of volatiles). Modern cans should have a pressure relief that vents if the pressure gets too high from what I remember. They can expand quite a bit before reaching that point though. It looks concerning, but they're intended to handle the pressure.

[Jammer]

Originally Posted by team karst

I suppose i also realize that keeping the vent open probably releases useful volatiles.
OK. balloons of pressurized gas will continue to ride with us. ��

Yes, the butane fraction is the first to go and with it cold starting ability in cold weather.

[thinwater]

Originally Posted by team karst

Any PChem folks out there? I read that gasoline has a vapor pressure of around 10 psi at 100 deg F
Does this mean my sealed plastic jugs will be expanded at half full same as full??

Maybe. The full can will take much longer to heat up than a nearly MT one. At the same temperature, the pressure does not depend on how much gas is in it.


You can also paint the tank white or cover it. Notice that all bulk gas tanks are white; it is the law.



Vapor pressure varies with the season and region. Ethanol gas is generally higher.

[MikeHoncho]

No the full can will not only produce the pressure from increased vapor pressure but the liquid will also expand. Don't fill a can shelf full. I couldn't find a Triple Point Chart for gasoline (they will be all a little different due to gasoline being a mixture) but at sea level and at 70F it will produce about 6 psi. I would assume it would be more than 10psi at 100F