What Is The 80/20 Rule?

Written By: on April 27, 2020

Learn more about how Superior Propane prioritizes your safety

80 percent tank fill flagstaff arizonaHave you ever gotten a propane delivery from Superior Propane, gone out to check your tank, seen your propane tank gauge level at 80% full and wondered if we’ve made a mistake?

We can assure you that we have not!

Our propane delivery driver filling the propane tank in your northern Arizona home to 80% full was no accident. It was completely intentional and done for your safety. Here’s an explanation, along with a science lesson behind it!

The science of propane

Propane (chemical formula C3H8) is a liquid. Like other liquid, it expands when it is heated. Propane in liquid form can’t be burned. To ignite so it can be used in your home’s heating system, water heater, range, or whatever appliance you are using it in, propane has to be able to expand.

However, propane expands a whole lot more than other liquids. An example: Propane expands at 17 times the expansion rate of water in the same conditions. You can read more about propane volume here.

With that kind of expansion, we have to leave some empty space in the tank so your propane has room to safely expand. Think about how hot it gets here. If the propane in your tank did not have room to expand, it could create a very dangerous situation!

That is why we use a fixed liquid level gauge to prevent overfills – one more way we work to make sure that every propane delivery is as safe as possible for you and your family.

Why do my propane tank gauge levels fluctuate?

This is a common occurrence. Again, think about how hot it gets here during the day. And then think about how cool it can get at night. That means there will be a lot of expanding and contracting of your propane going on. The tank gauge levels on your propane tank could fluctuate both up, and down, depending on what time of day you are looking at it.

Count on Superior Propane for safe, reliable delivery of propane. Contact us today to learn more, or to become a customer!