Frangible Roof Storage Tank
See figures 7 and 8.
Frangible roof storage tank. The reasoning behind present api design formulas is reviewed. In fact the frangible roof design fulfills the venting requirements due to deflagrations inside tanks for most tank sizes greater than about 35 feet in diameter. This paper presents the results of an investigation into the frangible joint behavior of tanks designed to api 650 rules. In such tanks the roof to shell joint is intended to fail in the event of overpressurization venting the tank and containing any remaining fluid.
A frangible roof joint forming a flexible gastight connection between a tank shell and a roof comprising an annular link mechanism sealingly secured at or adjacent a first edge thereof to a rim of the tank and sealingly secured at or adjacent a second edge thereof to the periphery of the roof. That is of course if the tanks are built according to the rules for frangible roofs.