Modernization of Old Steel Tanks Used to Store Liquid Fuels – Selected Tasks Caused by Increasing Environmental Requirements

Selected structural changes which have to be introduced in the existing on the ground tanks used to store liquid petroleum products, should these tanks be further kept in service under the same or modified service regimen, are discussed in this paper. Modernization of these tanks within the scope described by the authors is required due to the increasing environmental requirements. In particular, the improved sealing of the previously used single shell tank bottom structure has been considered. This may be achieved by adding an additional steel or composite second bottom with monitoring space, or alternatively by raising the whole tank and installing underneath it a geomembrane impermeable to petroleum materials and equipped with leak monitoring system. An application of lamination techniques with modern composite materials has to be accompanied with development and installation of a fail-safe system to ground the electrostatic charges generated by friction on the shells modernized in such a manner. The second modernization technology discussed in this paper is related to adaptation of the typical on the ground cylindrical storage tank equipped with floating roof to store the jet fuel. In this case the recommended solution is an addition of a lightweight aluminum dome.