What component in a hydraulic system prevents a vacuum from forming when the liquid level decreases?

In a hydraulic system, the reservoir plays a crucial role in maintaining system pressure and ensuring that a vacuum does not form when the liquid level decreases. The reservoir holds the hydraulic fluid and allows it to expand or contract as the system operates. When the liquid level drops, the reservoir design is such that it can accommodate this change without creating a vacuum, which could disrupt the flow of the hydraulic fluid and potentially damage the system.

If the reservoir did not effectively manage changes in fluid levels, negative pressure could lead to air being drawn into the system, resulting in cavitation and decreased efficiency. The reservoir also typically includes features such as a vent or filler cap that helps equalize pressure, further preventing the formation of a vacuum.

While pumps are essential for moving hydraulic fluid, and valves control the flow and pressure, neither directly addresses the issue of vacuum formation in relation to fluid level changes. Accumulators serve to store energy and maintain pressure, but again, they do not prevent vacuum formation specifically linked to fluid levels in the reservoir. Thus, the reservoir is the appropriate component to prevent vacuum conditions in a hydraulic system.