Why Propane Tanks Are Never 100% Full

Filling Propane Tanks
Superior Plus Propane

After a propane delivery to fill their tanks, many customers wonder why their tank gauge reads only 80% full. After all, completely full normally means 100% full. The reason for a “full” propane tank being only 80% full is simple—safety.

Why is there room for 20% more fuel in the propane tank when the tank is “full”?

Propane is stored in tanks as a liquid.  When propane is in the presence of heat, it will expand.  Therefore, there must be space in the tank to safely allow for the expansion of the liquid propane.  This is a safety measure to ensure that tanks will not explode when the outside temperature rises in warm seasons or climates (Why Are Propane Tanks Not Filled to 100% Capacity? – Propane HQ).

Propane companies generally follow the 80-20 rule as an industry practice.  The general practice is to fill the tanks to 80% of capacity to allow 20% space for expansion in warm weather.

Leaving Space in the Propane Tank Keeps Us All Safe

While it may seem like a “full” tank could hold more propane, the propane industry’s commitment to safety by following the 80-20 rule (and many, many other safety practices), allows for homeowners to use propane for their household needs safely.  No one wants to worry about the dangers of an over filled tank on a hot day.

Superior Plus Propane’s Commitment to Safety

We take pride in our commitment to the safety of our drivers and customers.  We follow the industry’s 80-20 rule, as well as investing in the latest safety technology and employee training to make sure that our customers and drivers can rest easy when it comes to propane deliveries.  For more information, please visit us at Propane Safety » Superior Plus Propane.


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