Prototech builds large capacity bins (silos) made completely from stainless steel, for storage, sterilisation, and transfer to production of sterile valves needed for packaging of spray-cream bottles, or other types of containers. The unloading hatch is designed according to the specific type of production plant and is capable, when production is finished, of keeping the remainder of the valves in a sterile condition for safe re-use. Its special design, control equipment and high capacity (up to 60,000 valves) allows the end user to reduce the risk of contamination due to a reduced number of hatch openings compared to smaller traditional containers.