Monolithic or bolted outdoor silos, in aluminium, stainless steel, painted iron or fiberglass, with smooth, mirror-like internal surface and load-bearing skirt support structure; equipped with safety valve for pressure/depression control, vibrating cone or fluid bed extraction, anchoring ferrule to the support platform, access door, loading pipe, vent pipe complete with filter, inspection porthole. They also have maximum and minimum level probes, safety valves for loading, anti-explosion hatch, weighing system, access ladder to the roof with gallery and parapet. Possibility of adding anti-condensation, dehumidification and insulation systems. The capacity varies from 10 m3 to 120 m3.