Originally shared on the public FactorioPrints / Factorio School archive (factorioprints.com · factorio.school). Authorship preserved from the public catalog.
This is a storage cell intended for a small factorissimo factory. Instead of forcing all the input to go though the chests, the input primarily bypass the storage. Storage is only filled when the belts overflow and supplement the input when it is to low. Improves throughput when the stored amount is low.