What is the term for a storage vessel that has a uniform diameter and is between 20 and 80 feet tall?

The term for a storage vessel that has a uniform diameter and is between 20 and 80 feet tall is "stand pipe." Stand pipes are typically vertical cylindrical structures used in water distribution systems that help manage water levels and pressures. They play a vital role in balancing the supply and demand for water in municipal systems, maintaining adequate pressure for delivery, and serving as storage that can accommodate variations in usage.

In contrast, a tank can have varying shapes and sizes, and while it can refer to any container for liquids, it doesn't necessarily specify the uniform diameter or the height. A silo primarily serves agricultural purposes, particularly for storing bulk materials like grains, rather than being dedicated to water supply. A cistern is designed for collecting and storing rainwater or groundwater, but again does not have the uniform structure specified by the question. Therefore, the characteristics outlined in the question align perfectly with the definition of a stand pipe.