How oil-free air compressor works

An oil-free air compressor is a variant of a rotary screw air compressor. The key difference between the air compressor and oil-free air compressor is, this compressor does not use oil on its cylinder walls or say it does not require lubrication regularly. The design has self-lubricating material which allows the piston to slide in the cylinder and the grease in the sealed bearing. 


The working principles of the oil-free compressor are the same as lubricating air compressors. Now the question arises: what is the need for an oil-free air compressor! It is difficult to keep the air clean when the process is exposed to oil, oil-free compressors the air is not directly exposed to oil which eliminates the risk of contamination. The mechanism includes a piston, rotary element that draws air, which is compressed into a storage tank.


Let’s just peek in the working, follow the steps, and see how it gets its job done. 

1. Draw air

The process begins by drawing air present in the environment through the valve, transferring the air through the air inlet filter, it makes certain of the air purity by straining out the dust, dirt, and debris.

The valves again open and allow the compressor to pump air into its chamber, when the valve gets close the compressor begins. While it is delivering compressed air the valve does not allow to draw more air in the inlet. After this stage, the air gets passed to the compressor element. 

 2. First compressor

Since it is working without any lubricant the compressor element lowers the air pressure. Because of this, the air compressor adds more features which means the compressor can operate at a higher temperature. The absence of lubricant prevents heat to whisk away. Oil-free element compresses the air and passes it through the compressor to cool down the air for further use. 

 3. Intercooler

After the air is compressed, the piston pushes the air through an intercooler where the air temperature lowers down for further compression. Depending on the design and nature of the compressor the intercooler either moves the compressed air to the second phase of compression or the final stage.

Intercooler not only cools down the air to an appropriate temperature and minimize the risk of heat damage but also allows air to be compressed at much higher PSI so the second stage can face less wear.

The process also filters moisture and water present in the air.

1. Second compression

The cold compressed air returns to the chamber where it further gets compressed by a higher pressure element. Due to the absence of lubricant, the process again increases the air temperature which again needs to be cooled down.

 2. Aftercooler

In the second phase, compression air temperature reaches around 150 degrees which requires additional cooling before it can come into use. This chamber lowers down the air temperature and passes it to the final stage where the air is properly stored to be used.

 3. Pressure switch

This switch detects the level of air in the compressor tank when it falls below a specific level the air compressor turns back and repeats the same process to fill the compressed aid back in the tank.

Advantages of oil-free air compressor 

The advancement of technology has enriched us with many products that are loaded with benefits, the oil-free compressor is one of them. 

Minimize the use of oil:

An oil compressor requires around 70 gallons of oil annually. The used oil needs to be properly disposed of, both processes cost a huge amount of money. In the oil-free compressor, there is no need to collect and dispose of the used oil; it reduces the overall cost used in oil.

Reduces maintenance cost:

After a certain time, the downstream filter stops filtering oil, which needs to be changed to resume the filtration. Oil-free compressor saves from the replacement.

The oil-free compressor is a one-time investment that lasts for a longer duration of time as compared to the oil air compressor hence there is no need to buy or replace any parts after a few years, oil-free compression lasts more than 7-8 years whereas oil compressor last for 3-4years.

Eliminate the risk of contamination

Oil-lubricated compressor always have a trace amount of 

oil in the air they produce, even the tiniest drop of oil can cause product spoilage or damage the product but an oil-free compressor provides the purest air, therefore, it eliminates the risk of contamination.

Safe for environment 

The oil-free compressor is quieter than other compressors which prevent the environment from noise pollution moreover it eliminates harmful emission, conserves natural resources, and gets a clean, reliable cost-efficient source of air supply. Along with the positive environmental impact, switching to an oil-free air compressor can have a significant impact on the total cost of ownership.