Oil-less compressors are often used when a certain level of air quality is required by the ISO (International Organization for Standardization). These applications usually include food and beverage production, medical uses, and applications involving chemicals. These compressors do use oil, however, a chamber keeps oil separate from the compressor itself. This is how contamination is prevented.
Oil-less compressors work in much the same way that the oil-free variety operates. The only difference is the location of the oil within the compressed air system.
We will dive into how exactly these compressors work in just a second. First, though, let’s go through the difference between oil-lubricated and oil-less compressors.
Oil Lubricated vs. Oil-Less Compressors
The main difference between an oil-lubricated compressor and an oil-less compressor is the location of where oil is used. Oil-less compressors do use oil. A chamber houses the oil keeping it separate from the compression chamber. Other materials lubricate the piston so it moves freely within the compressor cylinder.
On the other hand, an oil-lubricated compressor uses oil to lubricate the piston for air pressurization. Oil-lubricated compressors will often contaminate air produced by the compressor, even if the contamination is a trace amount.
How They Work
- Air Expulsion – The oil-less compressor runs through a set of steps during it’s “on-time”. The compressor first draws in air, pressurizes the air, and expels it.
- Filtration – The purpose of the filter is to eliminate any contamination to the air and ensure that no damage comes to other components within the compressor.
- Pressurization – The air is then pressurized within the compressor. Once the compressor completes the pressurization, it expels the air.
- Cooling – A cooling system cools the air as expulsion occurs, and a condensate drain collects any resulting liquid to prevent rusting.