We have a cylindrical tank with cross-sectional area, Ac. Liquid flows in at a rate Fi and

liquid flows out at a constant rate Fo. We want to control the tank liquid level h using a level

controller to change the liquid level set height hs. The available tank liquid height is HT. The

flow rate in the tank (Fi) is proportional to the percentage that the value is opened. We call

this set flow into the tank Fis.