Shoe seal for floating roof

A shoe seal for effecting a vapor barrier between a lightweight internal floating roof and a tank wall of a tank, comprising:

• a plurality of shoe sections each having upper and lower portions;
• a plurality of hanger brackets connected to bottom portions of perimeter sections of the lightweight internal floating roof, extending the bottom portions downward;
• a plurality of braces having first ends fixedly and rigidly connected to corresponding hanger brackets at positions vertically below the internal floating roof, and second ends rigidly connected to the floating roof, for supporting the hanger brackets;
• a plurality of pivoting support arms having first ends pivotally connected to corresponding hanger brackets at positions vertically below the internal floating roof and second ends pivotally connected to corresponding upper portions of the shoe sections;
• a plurality of hoop springs disposed substantially horizontally and connected at first ends to the internal floating roof and connected at second ends to corresponding lower portions of the shoe sections;
• and
• a vapor barrier fabric, a first end of the vapor barrier fabric being connected to the internal floating roof and a second end of the vapor barrier fabric being connected to the upper portions of the shoe sections such that a vapor seal is made between the shoe sections and the floating roof;
• wherein the upper portions of the shoe sections are maintained in contact with an inner side of the tank wall by pivoting action of the pivoting support arms;
• and
• wherein the lower portions of the shoe sections are maintained against the inner side of the tank wall by the plurality of hoop springs.