"Internal floating roof" means the cover or roof of a fixed-roof tank, which rests upon or is floated upon the petroleum liquid contained in the tank, and that is equipped with a closure seal or seals to close the space between the roof edge and tank shell.

Source. (See Revision Note at chapter heading for Env-A 1200) #9933, eff 6-1-11; ss by #12899, eff 10-17-19