Flamable Oil Warehouses

[@BillSmith-fx7xx]

Do oil storage tanks have floating lids to prevent a vapor containment in the void as tank levels get lowered ? It seems when I was a child I could see that from a high hill in the neighborhood. It looks like these days they all have some built-over-enclosure that is not really part of the tank, i.e. solid steel. Thank you.

[@xtermenterprises]

The roof of a floating roof tank floats on liquid stored at atmospheric pressure. As a result it rises and falls according to the liquid level, reducing the risk of vapor loss, fire and collapse of fixed roof tanks.