Confused? Safe or not? Don't wont to play with a bomb for a few cents savings.
Playing with a FIRE BOMB to be exact! If you do not know exactly what you are doing it can be disastrous.
PROPANE FACTS!
1) propane vapor is heavier than air it will accumulate in low areas
2) Liquid propane is lighter then water it will float
3) Liquid Propane weighs 4.24# per gallon
4) Liquid propane does not burn, but it creates massive amounts of burnable vapor
5) ONE GALLON of liquid propane creates 270 GALLONS burnable vapor
6) Liquid propane boils at -44F. and will freeze burn your skin and muscle immediately
7) Propane vapor only needs a static spark 2/3 of the power it requires the human body to feel in order to ignite
8) IT IS ONLY LEGAL TO FILL CYLINDERS BY WEIGHT
9) Propane has no smell an odorant is added
10) All small nonrefillable cylinders have a special odorant used to enable to test for refilling
11) All cylinders are equipped with relief valves in case of overfilling or overheating to prevent catastrophic cylinder explosion
12) Liquid propane expands 1% of it's volume for every 6 degrees F. above 60 degrees. and shrinks 1% of it's volume for every 6 degrees below 60 (60 degrees F. is the stable temp propane volumes are measured from)
13)Over filled cylinders can allow Liquid propane to enter appliances which is EXTREMELY DANGEROUS they must have a 20% vapor space measured at 60 degrees F.
14)NEVER TRY TO PUT OUT A PROPANE FIRE UNLESS YOU CAN CONTROL AND STOP THE SOURCE OF THE PROPANE THAT IS BURNING! due to the fact that the vapor can then accumulate and become explosive.
Now, if you still want to fill your cylinders too save a few dollars, PLEASE only do so if you know exactly what you are doing. A BURN CENTER IS NOT A FUN PLACE TO VISIT!