What Is an Oil-Water Separator and How Does It Work?

The Importance of Proper Condensate Management in Lubricated Compressed Air Production Systems.

Compressed air is important to a wide variety of industries; including manufacturing, medicine, and agriculture. It is utilised as both an energy source and in the production of many everyday items.

Lubricated compressed air production systems require large amounts of oil and water to concentrate the air into a particle-free state. Inevitably, cross-contamination of oil and water occurs. This creates a leftover condensate mix that is unsafe for both human and environmental consumption and exposure.

What is an oil-water separator? 

An oil-water separator treats wastewater by splitting oil and water into their respective components for safe discharge. Throughout the process, the device separates oil-water emulsions through natural filtration patterns and gravitational separation.

Oil-water separators are available in multiple sizes to accommodate existing compressor systems or fit into a new system layout.

How does an oil-water separator operate?

Traditional oil-water separators rely on gravitational separation. The wastewater condensate passes through multiple filtration chambers and utilises a filter bag to remove large particles. The collection chamber creates a natural, gravity-based filtration stage where oil droplets separate from the water and rise to the surface. The remaining oil particles are then absorbed by a floating polypropylene filter bag.

Cleaner condensate continues flowing from the bag into the second part of the chamber with a lower oil trace. In some oil-water separators, the second chamber includes an additional filter to separate the remaining oil from the condensate. Once the condensate has moved out of the chamber and through the exit valve, it is safe to be routed into the sewer system.

Maintaining Your Oil-Water Separator

Like any compressed air equipment, oil-water separators need proper maintenance to operate at peak-performance and make sure it is environmentally compliant. Unlike other devices that need frequent attention, oil-water separators are mostly self-sufficient and provide longer service intervals. Climate has a strong impact on the proper functioning of an oil-water separator. Each model should match the estimated humidity rates within the geographic region of your system to guarantee the cleanest results.

Cost-Benefit Analysis

There are several financial benefits to installing an oil-water separator into your lubricated compressed air production system. When oil-laden condensate has no outlet for filtration and disposal, it remains within your system. This causes deterioration of both the device and its end-product, leading to the need for equipment replacement and expensive maintenance.

Environmental and Economic Impact

Improper disposal of oil-contaminated condensate can lead to heavy fines from federal and local environmental agencies. Pollution from contaminated condensate harms the environment and prevents ecosystem development. Preparing your system for future regulations prevents the need to replace expensive equipment that no longer meets environmental protection standards, especially as environmental laws become more stringent.

In the United Kingdom, regulations require the oil trace in wastewater drained into foul drain systems to be at the maximum level of 20 ppm according to Chapter II, Par 85 (1) of the Water Resources Act of 1991. Failure to comply can result in fines up to £20,000 or up to three years in prison.

Choose the Highest-Quality Oil-Water Separator

Does your system need a new oil-water separator? Walker Filtration has a comprehensive range of oil-water separators varying in size and filtration capabilities designed to fit your lubricated compressed air system. Learn more about Walker Filtration’s SmartSep Series and its exclusive Organoclay filter cartridges here.

Contact us today at +44 (0) 191 417 7816 or sales@walkerfiltration.co.uk for further information about the Walker Filtration SmartSep Oil-Water Separator.