Positive Displacement Reservoir Breathers: An Active Method of Removing Moisture from Hydaulic Fluids, 2005 Engineering, Pulping & Environmental Conference

Recently, a number of companies have been promoting a variety of methods to limit contaminant ingression into oil reservoirs through the reservoir breather. These products include filter media for particulate filtration, hydrophobic media for blocking water droplets and aerosols, and desiccants to adsorb water and water vapor. These devices share a commonality in that they function by creating a barrier that prevents contamination (water or particulate depending on the breather type) from passing through. As they do not proactively remove contaminants from the fluid reservoir, they are functionally passive devices. Those that do address water ingression, do so by absorbing or creating a moisture barrier to restrict airborne moisture from entering a reservoir and contaminating the oil. However, water can ingress into the oil in many other manners, and being passive, these devices cannot remove it efficiently and therefore do not fully address the ultimate goal of continually maintaining the oil in a clean and dry condition.

A new optimized breather system utilizing a unique advanced separation technology has been shown to eliminate the introduction of free or dissolved water into reservoirs and will actively lower the dissolved moisture content of oil in lubrication and hydraulic fluid reservoirs. Installations in paper mill hydraulic areas have proven the system to be highly effective, in some cases reducing the moisture content of the oil by more than 150 ppm, which can double the operating life of hydraulic components. This improved fluid quality can substantially reduce maintenance expenses associated with repair and replacement of sensitive components such as servo valves and hydraulic pumps.