Addresses control valve applications for several thermal energy storage (TES) systems in which the water level of the storage tank is below the level of the piping in the building being served by the chilled water system. Also discusses valve-body and operator types as they relate to control algorithms, operating speed control, stability, positioner requirements, maintenance and manual operating capability.KEYWORDS: year 1996, Controls, energy storage, valves, chilled water supply, cisterns, algorithms