Where is my gauge located?
Your gas gauge is located under the dome at the top of the tank. Reading your gas gauge is not complicated. You'll see bold black numbers encircling the gauge and a single pointer needle. The pointer will indicate a number that represents a percentage.
Due to the physical properties of propane, your tank is considered full at 80% (allowing for the expansion of propane vapor). A propane tank is in IMMEDIATE NEED of refilling at 20%. For your safety and protection, it is best to fill your tank BEFORE the gauge goes below 20%.
Why isn't my tank filled to 100%?
Your propane is delivered and stored in liquid form. Propane liquid, for example, will expand nearly 17 times as much as water over the same temperature increase. As a result, tanks and cylinders are never completely filled with propane-gas liquid. Tanks are filled to about 80 to 85 percent of their capacity. This leaves a space above the liquid, which allows the propane liquid to expand freely due to changes in temperature.
There are several important characteristics that you need to understand about LP gases when they are stored in containers. First, heat added to LP gases in a tank or cylinder is transferred directly from the air surrounding the container. Hot days, cool nights, rain and snow are a few of the many factors that affect the temperature of the liquid. Because of these temperature changes, you may see fluctuations in your container gauge.