Learning about the 80/20 fill rule

If you’re a keen observer, you have probably noticed that a freshly-filled propane tank will read 80% on the gauge right after a delivery. Why not 100%, you ask?

Well, it’s actually no accident at all – it’s a propane safety measure.

You see, the propane in your tank is a liquid – and like any liquid, it expands when it’s heated. The difference with propane is that it expands a lot, and quickly – to the tune of about 17 times the expansion rate of a volume of water over the same temperature increase (you can read more about propane volume basics here, if you want to get even more technical!).

Our delivery technicians need to leave extra room in the tank to allow for propane to safely expand as the temperature of your outdoor propane tank rises (as your tank sits in the summer sun, for example*). Aboveground propane tanks are typically filled to about 80 percent capacity; underground propane tanks can be filled slightly higher, because the ground insulates the tank from big temperature swings.

As a propane safety precaution, Frank Lamparelli propane delivery teams use a fixed liquid level gauge to prevent overfills – one way we work to make sure that every propane delivery to your Massachusetts home a safe one.

For safe propane deliveries when and where you need them, trust the pros at Frank Lamparelli. Contact us to schedule a propane delivery today!

Frank Lamparelli – serving Boston Metro, Brockton, Plymouth, and surrounding communities from our headquarters in Canton, MA.

*Propane gas expansion is also a reason why you should NEVER paint your outdoor propane tank a dark color, since dark colors absorb heat!