General - Quality Requirements of Hydraulic Fluids
The quality of a hydraulic fluid is an
indication of the length of time that the fluids
essential properties will continue to perform as expected,
i.e., the fluids resistance to change with time. The
primary properties affecting quality are oxidation
stability, rust prevention, foam resistance, water
separation, and antiwear properties. Many of these
properties are achieved through use of chemical additives.
However, these additives can enhance one property while
adversely affecting another. The selection and compatibility
of additives is very important to minimize adverse chemical
reactions that may destroy essential properties.