A vacuum pump is a mechanical device that effectively removes gas molecules from a sealed volume, in order to create a partial or full vacuum.
These pumps are found in a wide range of industries, with applications including refrigeration, HVAC (heating, ventilation and air conditioning), medical equipment, laboratory processes and manufacturing.
For a vacuum pump to function as intended, it requires the right type of oil. The oil that is specifically formulated to suit these devices is vacuum pump oil.
In this article, we are going to look at what vacuum pump oil does, its characteristics, and the various types.
Purpose and characteristics of vacuum pump oil
Vacuum pump oil – manufactured by brands such as Fuchs – performs essential functions for vacuum pumps.
Firstly, it acts as a lubricant for internal moving parts. Secondly, it helps create a tight seal within the pump chamber, preventing moisture, dust and chemicals from entering the system.
Vacuum pump fluid also has the effect of cooling the pump and slowing wear.
Among the distinctive characteristics of vacuum pump fluid are; low vapour pressure, which prevents the oil from evaporating and contaminating the vacuum; thermal stability, so that it can function at high temperatures over a long period; oxidation resistance, to prevent breakdown and sludge formation; and chemical inertness, so that the oil doesn’t react with the gases or vapours it encounters.
Types of vacuum pump oil
We’ll conclude this article with a look at the various types of vacuum pump oil.
Mineral oil-based vacuum pump oil
The most common type, this oil is made from refined petroleum and is suitable for a range of general applications including industrial processes, oil-filled submersible pumps and rotary vane vacuum pumps. It may not be suitable for chemically harsh environments.
Silicone-based oil
With extremely low vapour pressure and proven thermal stability, this oil is used in diffusion pumps, dashpots and wet-type transformers. It is ideal for high-vacuum and ultra-clean applications, such as in semiconductor fabs or scientific research facilities.
Hydrocarbon-based and ester-based oils
These oils are used in specialty vacuum systems that require oil formulations with specific chemical resistances.
Choosing the right oil
Choosing the right vacuum pump oil always starts with consulting the vacuum pump manufacturer’s guide.
Be fully confident that you are using the correct oil type, to avoid issues such as compromised vacuum levels, substandard performance and damage to equipment.
