Impacts of Balance Valves on Pump Energy and Control Performance in Variable Water Flow Systems

There is no common agreement on the use of balance valves in the most popular variable water flow systems. A comprehensive theoretical analysis has been conducted to investigate the impacts of balance valves on initial cost, pump operation power, and system control performance. The investigation finds that eliminating balance valves can (1) reduce 20% to 40% pump energy consumption in a typical variable flow water system; (2) reduce the maximum pressure drop across control valves; and (3) improve pump efficiency at most partial load conditions. The reduced pressure drop across control valves improve system control performance and may allow selecting some of the control valves at lower close-off pressure. Consequently, eliminating balancing valves can also potential reduce system initial costs.