Why does a vacuum pump need oil?

One of the keys to keeping your vacuum pump in good working order is ensuring that it is operated properly and that the lubricating oil or fluid used in its operation meets the full requirements of the pump. Beyond reducing friction, your vacuum pump oil assists in cooling, controlling contamination, protection from corrosion, and creating fluid seals in the pump. Depending on your application, an oil’s volatility, vapour pressure and viscosity all play a part in achieving peak performance.
Volatility and Vapour Pressure

An oil with high volatility is more likely to turn from a liquid to a vapour as the temperature increases. Vapour pressure is the pressure with which the oil molecules try to escape the oil as vapour, since there is a tendency for liquids to evaporate. What this means is that a lower vapour pressure is preferred because less evaporation means less variance in the overall pressure and the pump performs more efficiently.

Why does a vacuum pump need oil?

Pump Oil Viscosity

Viscosity is often the primary consideration when selecting vacuum pump oil. The viscosity of a fluid is a measure of its resistance to flow – so low viscosity is thin and runny while high viscosity is thick and sticky. This is determined by the size of the molecules in the fluid. The essential consideration is that as temperatures rise, the viscosity of the fluid decreases and that can impact the flow of the oil as well as the seal between components. This is why it is so important to know what your pump requirements and applications are so you can choose the right oil to keep things running smoothly.
Vacuum Pump Additives

Additives in a motor oil differ from what might be found in a vacuum pump oil because they serve distinctly different functions. For example, motor oil may contain rust inhibitors that would separate from the base fluid and deposit on interior services as a gummy residue. Vacuum pump oil, however, is refined for use in a vacuum pump and may contain additives for corrosion resistance, anti-oxidation and anti-foaming. It is critical to understand the performance requirements of your vacuum pump as oils will react differently under high temperature and pressure conditions and the wrong oil can damage the vacuum pump while the right oil can promote long and healthy equipment life.
Let Intlvac Help You Decide

The choice of vacuum pump oils and fluids can seem difficult. We know that making the right fluid choice can mean the difference between a smooth running operation and frustrating down time. To help make your selection, check out this handy Leybonol lubricant guide before you buy. Still not sure? Give us a call at 800-959-5517 so we can help. And remember…our online store is open 24/7!