The performance of any hydraulic system is directly related to the quality of the hydraulic oil. The extreme conditions that hydraulic equipment is used requires additional consideration to help reduce wear and tear on system parts and reduce scheduled and unscheduled downtime.
Options in Additives
There are several considerations when choosing hydraulic oil additives. Each additive has a specific role in protecting the system and the metal parts and components when in use and during the startup and shutdown of the system. Typically, these additives are used in combination to provide the benefit required for the specific application.
- Antioxidants – oxygen in the base oil in a hydraulic system will oxidate over time. This process converts the oil molecules in the hydraulic system in a variety of potentially damaging compounds, including acids. It will also change the viscosity of the oil while increasing the formation of sludge in the system. Adding antioxidant additives slows this process.
- Corrosion inhibitors – as impurities in the hydraulic fluid increase with use, corrosion on metal parts becomes a concern. Adding corrosion inhibiting hydraulic oil additives protects metal surfaces from this problem.
- Viscosity improvers – these are polymers that are added to hydraulic oil to maintain viscosity. Without these additives, the heat and pressure in the hydraulic system breaks down the viscosity index and reduces the lubricating function of the oil.
- Anti-wear additives – as the name implies, these additives bond to the surface of the metal to create a sacrificial film. As the hydraulic oil loses the ability to maintain a protective thickness, the sacrificial film keeps the metal surfaces from making contact.
There are other hydraulic oil additives that are also beneficial. Defoaming agents, dispersants, and detergents can also be included for additional protection.
