Why was my propane tank not filled to 100%?

Ever wonder why we don’t fill your propane tank to 100% when we make a delivery to you? It all boils down to safety measures, a cornerstone of our propane delivery service.

Propane expands in the presence of heat – just like water, except much more quickly and at a much greater volume. In fact, propane increases to nearly 17 times the volume of water over the same temperature increase!

If your tank was 100% full and the temperature inside the tank rose (from the outdoor heat, for example), it becomes a dangerous situation.

That’s why our drivers only fill your above-ground propane tank to approximately 80 percent of its actual capacity (underground tanks will hold approximately 85% because the ground insulates them from big temperature swings). The extra space in the tank is a cushion against the pressure that builds up in a tank when it’s hot.

Our highly trained drivers actually don’t fill your propane tank by watching the level on the gauge, but by an even more accurate method which is based on when the bleeder valve emits liquid. This is an internal device in the tank which shows the tank is at it’s maximum safe capacity as the gauges can sometimes be unreliable. It’s one of the many measures we take to keep you safe at home.

To calculate the approximate fill capacity of your propane tank, multiply the tank’s total capacity by 0.8. Here’s a cheat sheet: