Fred wrote:How do I convert liters of propane to kilos of propane and back? Thanks.
There's just been a rash of people trying to convert from liters to grams, or moles to nanograms, or any variety of conversions from volume to mass, or mass to volume.
The answer to your question, as well as all of the others, deals with specific gravity. or density. Specific gravity is the property of a substance that tells us how much a specific volume of it weighs.
The "Benchmark" for specific gravity is water. One cubic centimeter of water, at 4°C, weighs one gram. This is the basis of most of the derived SI units, and a valuable concept to remember.
Now, you need to convert from Kilos to liters, not grams to cc. There are 1000 grams to a kilo, and remarkably, there are 1000 cc per liter. So there is one kilo per liter of water... Part of the marvel of the SI system!
Now all you need is the specific gravity of Propane. A quick web search lead me to
http://www.pmak.net/public/propane_facts.html where I find that liquid propane has a specific gravity of 0.504 g/cc - or, in the units you need, 0.504 kilos per liter.
To convert from liters to kilos, you would multiply by the specific gravity of 0.504.
To convert from kilos to liters, you would divide by the specific gravity of 0.504.