Article originally published on Noria.com.
Hydraulic efficiency in terms of hydraulic fluid depends on a few factors, all of which relate to the viscosity of the hydraulic fluid. Low viscosity, either from poor fluid selection or high temperatures, results in a loss of volumetric efficiency, overheating and wear. High viscosity, either from poor fluid selection or low temperatures, results in poor mechanical efficiency, difficulty starting up and wear.
Hydraulic pump and motor manufacturers have often based hydraulic fluid recommendations on viscosity requirements at startup, optimum running states and extreme running states. With this being the case, temperature control and/or controlling the viscosity fluctuations will be critical in managing the two main drivers of hydraulic pumping efficiency.