The Patty Vault is a vault containing many Krabby Patties inside. It appeared in the episode "Just One Bite" and made a cameo appearance in "Mermaid Man and Barnacle Boy VI: The Motion Picture." Though a refrigeration mechanism is never seen in the vault, it is assumed the vault is refrigerated because otherwise the Krabby Patties would start to expire and develop mold.
In "Just One Bite," it appears when SpongeBob sees Squidward eating many Krabby Patties in the vault, after visiting the Krusty Krab at 3:00 AM. Even though Squidward claims he hates Krabby Patties in other episodes, he becomes addicted to them in this episode. In "Mermaid Man and Barnacle Boy VI: The Motion Picture," it makes a cameo appearance in SpongeBob's movie.
The vault itself is made out of typical metal sheets of various sizes, bolted together. On the inside there are thousands of Krabby Patties lying around and stacked on top of each other, which indicates SpongeBob spends a lot of time and effort in cooking Krabby Patties. In large red writing on the front wall of the vault, it says "Patty Vault," in the same font that timecards and titlecards use. The vault seems much larger on the inside than it does on the outside. The inside is stocked full of Krabby Patties.