Skip to Content (press ENTER)

The Science of the Cylinder

Back to Blog List Page
Have you ever wondered what goes on inside your AmeriGas® Propane Cylinder? What kind of magic happens that cooks your food to such perfection? How does this substance power the outdoor heating lamps that keep you warm, or act as fuel in cars?

Ponder no longer! We are breaking down the science of the cylinder to ease your inquisitive yearnings and help you impress all your friends at your next cookout.

Propane (C3H8) is a versatile energy force that is more dense that air in its vapor form, but as a liquid, is lighter than water. 70% of the propane in use today is produced by refining natural gas. A “green” fuel, propane is colorless and odorless. However, in your cylinder, propane is in both its liquid and vapor forms and has a bit of a stench. In order for our senses to detect propane, an identifying (and stinky) odor called ethyl mercaptan is added.

The propane in the cylinder you pick up at any of our 45,000 convenient AmeriGas® Propane Exchange locations is 270 times more compact then the gas produced when the liquid boils. When propane boils, the cylinder gets cold, and the gas released is highly flammable, as shown with this special piece of training equipment.

Your cylinder also has an overfill prevention device (OPD) that prevents the cylinder from holding more than 80% liquid, leaving room for expansion when exposed to warmer temperatures and higher pressure.

(AmeriGas employee from Commerce City, CO, Chris Selepec, displays the OPD in a cut-away demonstration cylinder Source: Steve Spangler Science)

Because propane is one of the lightest, simplest hydrocarbons in existence, it is also one of the cleanest burning of all fossil fuels. It does not harm soil, water, or contribute contaminants to acid rain. This is why propane is an approved, clean fuel according to the 1990 Clean Air Act as well as the National Energy Policy Act of 1992.

Now that you know what goes on inside your cylinder, go pick up a spare and spread the word!