Do I Need an Oil-Free or Lubricated Compressor? - Atlas Copco Sweden
Our solutions
Kompressorteknik
Solutions
Industriverktyg och monteringssystem
Solutions
Industries Served
Industriverktyg och monteringssystem
Energiteknik
Solutions
Produkter
Energiteknik
Energilagringssystem
Produkter och lösningar
Solutions
Oljefria luft- och kväveboosters
Borrmaskiner
Produkter och lösningar
Uthyrningspark
Produkter och lösningar
Energilagringssystem
Produkter och lösningar

Do I Need an Oil-Free or Lubricated Compressor?

Compressor Types Compressors Choosing an Air Compressor Compressed Air Wiki How-To

Once you have the size and type of compressor figured out, one last question remains, should I go with an oil lubricated or oil-free air compressor. To not overcomplicate the answer, your choice should be based on the application and process that the compressed air will be utilized in.

Do I need an oil-free compressor?

do you need an oil free or oil lubricated compressor? find out.
The first step in selecting any compressor is assessing your facility’s needs. There are instances where the consequences of oil contamination are too high, therefore having an oil-free air compressor is a must. However, the majority of manufacturing, industrial and small workshops utilize oil injected compressors, since the consequences of oil contamination are not as great as they would be in a food production facility for example. Oil in air compressors is utilized to lubricate, seal and also cool the compressed air. If there is no immediate need for oil-free compressed air, the more economic way is to go with an oil lubricated unit like an oil-injected screw compressor. Oil-free compressors carry a much greater cost. Although, there are traces of oil in compressed air, those can be cleaned up further by utilizing proper quality air products. The use of coalescing filters can clean the compressed air down to 0.01 micron, which can further be cleaned by adding a carbon activated filter to get close to Class 1 air purity.

What are the different air purity classes?

Oil-free air compressors are used to produce a wide range of sensitive products, from semiconductors, medication and paper. Even the smallest trace of oil in such applications could have adverse effects on products and even people. Class 0 and “technically oil-free” are often used to imply that a compressor meets certain standards. Although, these terms are similar they have key differences that if not taken under consideration can lead to unintended consequences.

To better understand it all, let’s take a deeper look at the meaning of 'Oil-fee'. Oil-free and oil-less are both used to describe compressors that do not use any lubrication in the compression chamber. While the first two terms describe a type of compressor, Class 0 and “technically oil-free” express how clean the air is after compression. There are important differences between the two, which we will explain later on in this article.

The International Organization for Standardization (ISO) sets forth worldwide standards for proprietary, industrial and commercial purposes. Compressed air has its own set of ISO standards. Depending on the ultimate air purity (determined by number of particles per cubic meter as a function of particle size), compressors can be ranked from ISO Class 0-5. The original version of ISO compressed air purity standards (1991) was ‘made by and made for’ the filter manufacturers. The standard defined five classes of oil concentration, the best of which was Class 1.

 

ISO Class 1 - Technically Oil-Free Air

Class 1 specifies an oil concentration of 0.01 mg/m3 at 1 bar(a) 14.5psia and 20oC (68F), and conformance to these criteria is sometimes called “a technically oil-free solution.” However, these standards were edited in 2001 and were further updated in 2010. The current standard sets limits on total oil content (aerosol, liquid and vapor), and a specific standard was introduced on measurement of oil vapor. 

 

ISO Class 0 - Oil-Free Air 

A new class (Class 0) was added to cover more stringent quality requirements. ISO Class 0 is the cleanest choice. They can guarantee 100 percent oil-free air. There are some faulty claims going around the industry that promote oil lubricated compressors with filters and calling them “technically oil-free” as well as stating that the air quality is often better than that from an oil-free compressor. These claims are untrue and their use when Class 0 is needed can lead to inadvertent damage to sensitive products and or equipment.

When choosing an oil-free compressor, make sure to pick a Class 0 oil-free compressor and not a “technically oil-free” option. They generally have a higher initial price point, but they are much safer to use in sensitive applications. With Class 0, you can be sure that absolutely no contamination will reach your end user equipment and rest assured that your assets are protected. It is always best practice to seek advice from a compressed air professional when picking out an oil-free or oil lubricated air compressor.

Other questions when buying a compressor

What Compressor Size do I Need?
What Compressor Size do I Need?
Find out what the size of your copressor should be, based on the required air flow and pressure.
 
Find out what the size of your copressor should be, based on the required air flow and pressure.
Find out what the size of your copressor should be, based on the required air flow and pressure.
What Type of Compressor Do I Need?
What Type of Compressor Do I Need?
Find out what compressor is best suited for your needs.
 
Find out what compressor is best suited for your needs.
Find out what compressor is best suited for your needs.

Kompressorer finns i alla typer och storlekar. Det finns en kompressor för alla, från enorma maskiner som håller igång gigantiska produktionsanläggningar till de små versioner som används av entusiastiska ”hemmafixare”. Med så många modeller att välja mellan, vilken är den rätta kompressorn för dig? Den här guiden hjälper dig att fatta rätt beslut för ditt företag.

 

Vill du be en av våra experter om råd? De hjälper dig gärna att hitta den optimala kompressorn.

 

Check out our wide range of reliable, energy-efficient and cost-effective air compressors. For all your low, medium and high pressure applications.