Propane is pretty amazing stuff. We can cook with it, heat with it and loosen rusted hardware. Propane is sold in small tanks like those used in "Bernzomatic" and other hand held torches and it is sold in 20 pound and 30 pound cylinders for camping trailers and gas grilles.

When you buy propane in a cylinder you buy liquid propane. It remains a liquid under pressure because of its physical characteristics. When you open a propane cylinder which is upright you get the gas component to flow out of the tank. As you use the gas it is replaced by more gas due to the fact that the pressure inside the tank drops and the liquid propane boils, releasing propane gas from its surface. When this happens the liquid propane gets cold - very cold! How cold does it get? Well, if you were to get liquid propane in your eyes it will boil rapidly and get so cold that it will freeze your cornea (the outer surface of your eye) and render you blind in a matter of a second or two. That is very important to know when you are around that kid who is filling your 20 or 30 pound cylinder for the gas grille. You should never stand near the filling station unless you are wearing safety glasses with side shields - and the person filling the tank should be wearing the same, but they never do! If you are ever getting your tank filled and the operator doesn't wear safety glasses don't hesitate to ask him where his safety glasses are. If it is a kid then make sure the owner of the store knows that safety glasses weren't worn and tell him of the dangers of liquid propane to the kid's vision!

Because propane is a liquid you can easily tell how full your propane tank is, be it the small hand held tank or a larger tank for the gas grille or camper. Simply pour hot water down the side of the tank, wait a second or two and then slide your hand up and down the tank. It will remain quite hot where there is no propane behind the steel wall of the tank, however the heat will be rapidly absorbed from the tank surface by liquid propane. So, you can tell where the liquid level is by feeling the temperature gradient on the tank surface with your hand. Where the tank goes from hot to cold is where the liquid level is. Simple, huh?

Back to Brother Bob's Home Page

Copyright © 1996, 1997, 1998 by Bob Hewitt - All rights reserved