Myth: Compressed air contamination is a compressor issue.
Fact: In a typical compressed air treatment system, contamination comes from three different sources, these being:
- Atmospheric air: Air compressors draw in huge amounts of atmospheric air, which continuously fills the system with contaminants such as water vapor, microorganisms, atmospheric dirt, and oil vapor.
- The air compressor: In addition to the contaminants drawn in through the compressor intake, the compressor also adds particulates from its operation. Additionally, oil lubricated compressors carry over liquid oil, oil aerosols, and oil vapor from the compression process. Once through the compression stage, the after-cooler will also condense water vapor. This introduces it into the compressed air in both a liquid and aerosol form.
- Compressed air storage devices and distribution piping: The air receiver (storage device) and the system piping that distributes the compressed air around the facility both store large amounts of contamination. Additionally, they cool the warm, saturated compressed air which causes condensation on a large scale. Thus, adding liquid water into the system. This saturated air and liquid water leads to corrosion, pipe scale, and microbiological growth.
Myth: Static oil water separators are not suitable for synthetic lubricants/PAGs. This is evident with cloudy outlet water.
Fact: Oil water separators are designed to reduce oil in water levels to acceptable limits. Some lubricants such as synthetics/PAGs also contain detergents and additives to extend the life of the compressor. Oil water separators are not designed to remove detergents and additives. Lab analysis needs to accurately determine oil in water content and not from visual inspection. Lab analysis of cloudy outlet water is the only way of accurately testing oil in water content to show whether or not it is within acceptable limits.
Myth: Any dryer (refrigerated or desiccant) can be installed outdoors.
Fact: A standard dryer design is for internal installation. However, many are often installed outside, with or without a lean-to roof. Outside installation is acceptable provided there is a lean-to roof with freeze/snow protection, blowing rain protection, and a roof/ceiling high enough to avoid hot air recirculation. We do no recommend outside installation of standard dryers with no roof.
In a case where outside installation without roof is a necessity, request an outdoor modification package including freeze protection, UV protection in paint, fasteners and electronics, and Nema 4 components throughout. A Nema 4 electrical enclosure alone is not sufficient for an outdoor setup without roof installation.
Myth: Most dryers do not provide dryness levels to the same levels quoted in sales literature.
Fact: Dryer installations often plague with a variety of mistakes which impact the level of compressed air dryness they provide. Classic installation mistakes are:
- Insufficient space above or in front of condenser air discharge, which causes recirculation and high pressure faults
- Dramatic undersizing of dryers, forgetting that cooling water and ambient air in summer is at far higher temperatures than in winter
- Insufficient power supplies, so the actual voltage is subject to tremendous dips, which can wreak havoc with dryer operation and performance.
Myth: Compressed air filters also dry compressed air.
Fact: Compressed air filters are capable of removing bulk liquid water and some water aerosol from compressed air. Compressed air filters are not capable of reducing the level of moisture vapor in compressed air. Nor do they reduce the pressure dew point of compressed air.
We hope this information helps those working with compressors to increase your understanding of your machines! We also hope we broke down all this air treatment myths you might’ve thought were true! Whether you’re looking to purchase a compressor or are in need of maintenance, 3C dedicates to educating our customers and providing quality service and products. Contact us for more information today!
