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Why Isn’t My Propane Tank 100% Full After Delivery?

There’s Some Basic Science Behind This Safety Step

propane tank franklin county, vt If you’re the type of customer who checks the gauge on their propane tank after a propane delivery, you’ve probably called us to as why it’s not completely full when we leave. It’s a good question—we get it: If you’ve called us to come fill your tank, why isn’t it full? The answer is right out of your high school chemistry book.

What Is The 80/20 Rule?

Although it flows through pipes in your home in the form of a gas, propane, also called LPG or liquid propane gas, is transported and stored in a liquid form. And if you paid attention in chemistry, you know that liquids expand when they are heated. What you may not know is that liquid propane expands a lot more, and a lot faster, than some other liquids. Propane will expand nearly 17 times more than water that’s heated the same amount. That’s the reason that an aboveground propane tank, which is exposed to the sun, is considered “full” at about 80%. That extra room provides a cushion against the pressure that builds up inside the tank. Underground propane tanks are typically filled to about 85% because they are insulated from the sun’s heat.

You might notice that the propane tank gauge reading fluctuates slightly during quick temperature swings (hot day, cool night), but don’t worry, that’s perfectly normal. The amount of gas in the propane tank doesn’t actually change when propane expands or contracts–only its density does.

Will Call Service or Automatic Delivery

Remember, although your propane tank will never be filled to more than 80%, you should always call for a fill-up before your tank falls below 20% so we have time to schedule a delivery. If your tank falls below that level, you could lose pressure, which can lead to problems with equipment.

Of course, checking your propane tank level is an easy task to forget about. That’s why we give you easier ways to make sure you get propane deliveries when you need them—without having to remember to check your propane tank and call us for delivery.

Our automatic delivery service that takes watching your propane tank off your to-do list. We use a proven system based on your previous usage and other factors to let us calculate when you will need a propane delivery. Automatic delivery makes things easier on our end, too: We’re better able to plan deliveries, using the most efficient routes to get to everyone quickly. That saves time and money—savings we can pass on to you.

Of course, we still believe in old-fashioned customer service. That’s why we’re always happy to take your call and answer any questions. Contact us today to sign up for worry-free automatic deliveries or ask about our propane monitors.