Difference Between Hydraulic Oil & Pneumatic Oil

by Jared Ruplinger

Hydraulic oil and pneumatic (lubricating) oil are two different fluids for entirely different applications. It is important to understand these differences when selecting an oil to use. Choosing the wrong fluid could result in equipment failure or injury.

Hydraulic and Pneumatic

Hydraulic systems use a liquid, such as oil, under pressure to power cylinders, valves, motors and so on. Pneumatic systems use a gas, such as air, under pressure, to power cylinders, valves, motors, among other equipment.

Hyrdaulic Oil

Hydraulic oil, sometimes called hydraulic fluid, is used to transfer energy from one component to another in a hydraulic system. There are several types of oil that may be used in a hydraulic system depending on the individual application. Different oils have varying viscosity and compressibility. The machinery being used typically specifies which type of hydraulic oil is required.

Pneumatic Oil

A pneumatic system is powered by compressed air.

Pneumatic oil, more frequently called lubricating oil, is used to lubricate the moving parts in a pneumatic system. Pneumatic oil typically has a low viscosity and is easily atomized so it can be transported by the compressed air in the system. Some systems will have an oil reservoir that automatically dispenses lubricating pneumatic oil, while others require the operator to manually add a few drops of oil every so often.

About the Author

Jared Ruplinger is an entrepreneur and journalist who has been writing since 1995. He has worked in and written about fields ranging from world travel to e-commerce and manufacturing processes. He has also written for the "Catalina Islander" newspaper and other publications. He holds a Bachelor of Arts in anthropology and Japanese.

Photo Credits

  • photo_camera hydraulic machine image by Heng kong Chen from Fotolia.com