refillable propane cylinders

[OkeeDon]

<font color="blue">The state of propane is dependant on pressure and temperature.

For example: you can obtain an open bucket of propane at atmopheric pressure if the filling process produces enough expasion-cooling to liquify the propane. Just don't put your finger in the liquid to check on temperature though. </font>

Yep. Propane boils at -44 degrees F. I'm told that in some areas of Canada, in the Winter, one can walk around with an open bucket of propane because the ambient temperature is colder than -44 F. I had a friend from Upper Michigan who told me he was heading to the garage to build a charcoal fire under his oil pan in order to start his truck. Without thinking, I asked him why he didn't use a propane burner. He reminded me that propane won't boil and vaporize to a gas in Upper Michigan in the Winter...

 

[Egon]

One can fill a bucket with propane in nice warm midsummer temperatures. It takes about six or more hours to evaporate at 70 degrees farenheight.

Uh - worked in a plant that had several small fractionation trains that could produce about 2500 cubic meters of propane a day.
All that is required is pressure differential and a valve that will not freeze up.

And yes - people have built wood fires under propane tanks in severly cold temperatures! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

Egon /forums/images/graemlins/grin.gif

 

[dixiedrifter]

If one takes a bottle of propane and refills it, it should not be more than 80% full anyway.

The entrance to the bottle is approximately 50% of the volume. Meaning if you flip your big tank upside down (which I think ya gotta do), the little tank is sitting at 90 degrees horizontal.

The propane will only go down into it about 1/2 to 2/3rds of the little cylinder cause of the propane "bubble" formed in the top of the cylinder.

The bubble would have to go back into the big tank to let more liquid propane in, and it can't cause the entrance/exit of the little bottle is submerged in propane, thus preventing overfilling.