Why is valve called valve?

Why is valve called valve comes from etymology and function, as the word valve originates from Latin valva meaning leaf of a folding door, and later used to describe a device that opens and closes to control flow, similar to a door. The term was used in Middle English to refer to a flap or folding door, and by 15th century it was applied to parts of body like heart valves that open and close like doors. In mechanical engineering, a valve is called valve because it acts like a door or gate that controls passage of liquid, gas, or vapor through pipe by opening, closing, or partially obstructing, essentially regulating flow just as door regulates entry. The name reflects its door like action, leaf that moves to allow or block. In company name Valve Corporation, founders chose Valve as name because it reminded them of valve as mechanism that controls flow, and also as nod to earlier company and feeling of being gateway to entertainment, though they have said they liked sound. So valve called valve because it functions like a small door that controls flow, opening to let through and shutting to stop, analogous to folding doors in Roman architecture where word originated, describing leaf that folds to open and close.