Section 211.2190  External Floating Roof

"External floating roof" means a cover over an open top storage tank consisting of a double deck or pontoon single deck which rests upon and is supported by the volatile organic liquid being contained and is equipped with a closure seal or seals to close the space between the roof edge and tank shell.

(Source:  Added at 17 Ill. Reg. 16504, effective September 27, 1993)