How many stories are hydraulic elevators usually limited to?

Hydraulic elevators are typically limited to around 5 or 6 stories due to their design and operational constraints. This limitation arises from the mechanics involved in hydraulic systems, which utilize a pump to move fluid and lift the elevator car. As the height of the building increases, the amount of hydraulic fluid needed and the mechanism to support the weight of the elevator and its occupants becomes more complex and inefficient. Thus, for higher buildings, traction elevators are preferred due to their ability to handle greater heights and loads more effectively.

The 5 to 6 story limitation for hydraulic elevators makes them well-suited for mid-rise buildings and low-rise residential applications, where their efficiency and cost-effectiveness are advantageous. This context highlights why the other options, which suggest higher limits, do not align with the common practices and technical capabilities associated with hydraulic elevator systems.