In order to allow for liquid expansion, propane containers are typically filled to ______ % of their capacity.

In order to allow for liquid expansion, propane containers are typically filled to ______ % of their capacity.

• A. 60%
• B. 80%
• C. 90%
• D. 100%

Answer: (B)

Propane expands when it’s heated, so tanks must have space inside to accommodate that expansion without building dangerous pressure. Filling a tank to about 80% of its capacity leaves enough headspace for the liquid to expand into gas as temperatures rise, keeping pressure within safe limits. Filling to 100% would remove that safety margin and could cause venting or tank failure; going much lower would waste capacity without added safety. So 80% is the standard that balances safe operation with usable fuel.

Propane expands when it’s heated, so tanks must have space inside to accommodate that expansion without building dangerous pressure. Filling a tank to about 80% of its capacity leaves enough headspace for the liquid to expand into gas as temperatures rise, keeping pressure within safe limits. Filling to 100% would remove that safety margin and could cause venting or tank failure; going much lower would waste capacity without added safety. So 80% is the standard that balances safe operation with usable fuel.