Metallic structure which floats on the surface of a liquid inside an open top tank shell, and in complete contact with this surface.
A Pressure/vacuum relief valve Pressure/vacuum relief valve is an umbrella term that includes pressure or vacuum relief valve as well as pressure and vacuum relief valve. floating roof Floating roof A floating roof is the roof of a tank that is fitted with floating chambers (pontoons) and lies on top of the liquid. is the roof of a tank that is fitted with floating chambers (pontoons) and lies on top of the liquid. The roof rises when the tank is filled and lowers when the tank is emptied.
