Reducing Oil Carryover in an Oil-Flooded Air Compressor

Table of contents

If you require ultraclean compressed air in your processes, it is important to reduce oil carryover as much as possible.

Here’s what you can do:

Use Intake Filters to Reduce Contaminants Coming into the Compressor

The intake filter is your first line of defense against contaminants in your compressed air supply. The intake filter will remove large particulates and some oil mists from atmospheric air entering the air compressor.

Use Inline Filtration to Remove Oil and Particulates from Compressed Air

The inline filters for sale do most of the work in reducing oil carryover from an oil-flooded air compressor.

A high-efficiency coalescing inline filter removes particulates down to 0.01 microns and has a maximum oil carryover of 0.008 PPM.
Activated carbon inline filters remove hydrocarbon mists, vapors, and odor with a maximum oil carryover of 0.002 PPM.

With these filtration efficiencies, there is very little meaningful difference in compressed air quality between an oil-free and oil-flooded air compressor. In fact, inline filtration for an oil-flooded air compressor may be more efficient than a filter used with an oil-free compressor, because the filters work best when they have some oil in them.

Change inline filters at least once a year or after 8,000 hours of operation.

Use an Oil/Water Separator

The oil/water separator is used to separate lubricants from condensate generated by the air compressor. The oil/water separator removes excess oil from the compressed air condensate and allows for proper disposal of liquid wastes according to EPA guidelines. The oil/water separator must be properly maintained, and filter cartridges should be changed at least annually.

Test Your Air Supply Monthly

If ultraclean air is a necessity, make sure you test your compressed air supply at least monthly to make sure oil carryover isn’t rising. If you start to see an uptick in oil carryover (measured in PPM), check your inline filtration. It may be time to replace the filters.

How is Oil Removed from Inside an Oil Flooded Compressor?

Internal to the compressor is an air/oil separator, this device removes oil from the compressed air discharge so that the air has less than 3 PPM of oil in it, the inline filtration takes care of the rest. At one time years ago the separator was a common failure point for lubricated air compressors. However, with modern designs, that is rarely an issue anymore. An air receiver tank can be added after the compressor to act as a failsafe to prevent oil from reaching the compressed air filtration and air distribution system in the unlikely event of a failure.

Can You Get Oil-Free Air from an Oil-Flooded Air Compressor?

Can an oil-flooded air compressor be used for applications requiring ultraclean compressed air? In most cases, the answer is yes. Fluid-Aire Dynamics can help you transition from oil-free to oil-lubricated air compressors with high-efficiency filtration. We helped one manufacturer make the switch nearly 30 years ago—and their air has passed every air quality test since.

Want to know which kind of air compressor is right for you? Talk to a compressed air expert at Fluid-Aire Dynamics. Call or contact us online.