The flame heats any surrounding gasoline so it releases gases at the same time. Once the flame ignites the gases, the fire spreads. Common fire suppression systems include h2o sprinklers, which might be activated by heat; foam systems, used for Course B fires; CO2 systems, usually used for electrical fires; https://car-park-extract-systems23445.blog4youth.com/37273980/fire-rated-ductworth-insulation-for-dummies