Frozen Butane!!

[figbat]

I thought Gaslite bottles were Propane?

They are/were - but even so, under heavy use (eg patio heater) they could get cold enough to significantly reduce gas flow. I spent some time with the team that developed the cylinders during their launch.

 

[JTQ]

Very much the same goes for metal bottles in normal humid conditions, the intense chilling to support very high gas draw off levels quickly forms an ice jacket on the bottle as the air's humidity freezes out, forming a pretty good thermal barrier.

 

[gary]

It won't get cold enough to stop Propane gassing in any bottle, minus 140C odd!
However gas draw off rate can and does freeze the regulator preventing gas getting out

 

[figbat]

It won't get cold enough to stop Propane gassing in any bottle, minus 140C odd!
However gas draw off rate can and does freeze the regulator preventing gas getting out

With lowered temperature comes lower vapour pressure - it can get low enough to not fulfil the demand for a high flow application, like a space heater. We’re not talking about freezing the propane solid, just reducing its boiling rate enough to be ineffective.

 

[JTQ]

It won't get cold enough to stop Propane gassing in any bottle, minus 140C odd!
However gas draw off rate can and does freeze the regulator preventing gas getting out

Are you confident it is so low Gary? Most refences, and my memory, give its boiling point as around -42 C .
LINK 1 LINK 2

With the bottle getting well covered with thermally insulating ice, this is not IMO altogether an unobtainable low liquid temperature.
Certainly, any airborne moisture in the regulator's atmospherically vented side, could quickly run into causing several issues.

All said, when it comes to caravanning, I will not be venturing out even with propane, in an ambient any where near not being able to use the heater!

 

[figbat]

The propane will still give off gas below its boiling point - remember that it is liquid in the cylinder at ambient temperature (because of the pressure it is under). This is where vapour pressure comes in. Example: water - leave a puddle of water at room temperature and it will eventually all evaporate even though it doesn’t boil - it’s the same with any volatile liquid. Cooling it down will lower the vapour pressure meaning it will evaporate less readily. The only way to prevent it evaporating completely is to freeze it solid.

Nonetheless, the BP Gas Light bottles suffered with reduced gas pressure due to evaporative cooling when used in high demand applications, because of the thermally insulating properties of the cylinder material.