Oil is not what it seems...
August 10th 2007

Ask most maintenance or production engineers, what they considered to be the major contaminant found in their compressed air system and their answer would almost certainly be oil.

In reality however, oil is not the major problem perceived by so many. In fact, the most prolific contaminant is water and up to 99.9% of the total liquid contamination found in a compressed air system is water. This means that oil only attributes a very small percentage of the overall liquid contamination.

Understanding the sources of compressed air contamination and the types of contaminants which must be eliminated is fundamental to understanding the principles of effective purification system design.

Sources of contamination in a compressed air system include the atmospheric air and the type and operation of the air compressor.

Types of contamination found in a compressed air system include: Atmospheric dirt, Water vapour, condensed water and water aerosols, Rust and pipescale, Micro-organisms, Liquid oil and oil aerosols, Oil vapour, So why is oil seen as the major contaminant?

Oil is only perceived to cause the most problems as it is can be seen emanating from open drain points and exhausting valves. In the majority of instances, it is actually oily condensate (oil mixed with water) that is being observed.

To read the full article, which includes advice on the technologies available for removing contaminants from a compressed air system, click here.

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