Abstract: A sealing system for a liquid storage tank having a pontoon roof or cover floating on the liquid product contained within the storage tank. A stepped metallic shoe is constructed to maintain contact with the inner wall of the liquid storage tank which, in cooperation with a vapor impermeable fabric skirt, functions as a primary seal. A secondary seal, having an "E"-shaped cross section functions to maintain vapor integrity. The structure of these two seals is especially suitable for, respectively, sealing horizontally and vertically disposed rivet seams.

Abstract: A sealing system for a liquid storage tank having a roof freely floating on the contents stored within the storage tank. The sealing system is in wiping contact with the tank shell and may utilize a primary and a secondary seal. As a primary seal, the system forms a seal above the liquid level and eliminates capillary action of the liquid between the seal and the tank shell. The sealing system also exerts a continuous pressure against the inner walls of the storage tank preventing the storage tank roof from shifting due to wind loading and effectively preventing vaporization of the liquid due to wind effected negative pressures. As a secondary seal, the system acts as a vapor barrier preventing vapors from escaping and preventing contaminants from entering into contact and deteriorating the primary seal which could result in contamination of the liquid contained within the storage tank.

Abstract: A sealing system for a liquid storage tank having a roof freely floating on the liquid contained within the storage tank wherein a plurality of shield sections are structurally interlocked to eliminate the need for a vapor-impermeable fabric annulus overlying the shield and interface between adjacent sections of the shield and effectively preventing vapor from escaping from the tank and contaminants from entering into the liquid. The structural interlocking of adjacent shield sections provides a uniform distribution of the forces and counter forces exerted between the floating roof and the inner wall of the tank shell due to wind loading.