Propane

Propane is a liquefied petroleum gas used as fuel in hot air balloon burner systems. In the cylinder it is stored mainly as a liquid under pressure and changes to gas before burning in the burner. Because propane gas is heavier than air, a leak can collect in low areas and create a fire or explosion hazard. A pilot checks the fuel quantity, valves, hoses and smell of gas, and keeps ignition sources away if a leak is suspected.