ABSTRACT
Hydraulic fluids are one of the most commonly used industrial lubricants. The use of hydraulic fluids relative to other industrial lubricants is shown in Figure 32.1 [1].
The purpose of a hydraulic fluid is to transmit power from one location to another. The transmitted power is used for performing specific functions. In addition to transmitting power the hydraulic fluid must also lubricate moving parts and protect them from corrosion. A certain amount of load carrying capacity is also generally expected out of a hydraulic fluid. One of the earliest hydraulic fluids used was water. However, water was quickly replaced
by mineral oils. Subsequently mineral oils evolved into R&O oils and then anti-wear hydraulic fluids. The fluids in current use are complex and highly formulated anti-wear hydraulic fluids [2].
