In modern times many hydraulic equipment manufacturers specifies the new oil cleanliness, depending on the hydraulic application. At sensitive components and high working pressure, the required cleanliness is more stringent than a decade ago. For performance servo and high-pressure systems is recommended oil cleanliness according ISO4406 of 16/14/11 or better. One of the causes of ingress of contamination into a hydraulic system is by introducing unclean new oil.
Turbine oil exists for more or less 97% of base oil and 3% of additives such as demulsifiers, corrosion inhibitors, oxidation inhibitors and defoamants. The different types of turbine oil are made for a specific application, a gas-turbine requires a different oil type than a steam turbine or a combined cycle turbine. Each have their typical ingredients and blends to meet their special needs and to counter specific problems.