Hydraulic Oil Filtration
Hydraulic systems are the lifeblood of modern manufacturing, marine, and construction equipment. However, hydraulic oil filtration is often overlooked until a pump failure occurs. Effective oil filtration is not just about catching large particles; it is about preserving the fluid’s chemical and physical properties to ensure lubricity and power-transfer efficiency.
Although highly sophisticated, today’s hydraulic oil filtration systems use traditional full-flow filters to clean the hydraulic oil. As the rising number of costly hydraulic system failures in the industry shows, this approach is insufficient. Water contamination is one of the primary factors that can reduce hydraulic oil’s lifespan, leading to internal surface corrosion and increased wear due to inadequate oil lubrication. The contaminated particles reduce rolling bearing life, causing internal wear on hydraulic components and leading to leaking seals. Plant or equipment failures due to sticking pilot valves are also, in many cases, a direct result of fine contaminated particles in the hydraulic oil.
Contaminated particles about the same size as the equipment clearances should be removed. The condition of the hydraulic oil will determine the machinery’s uptime and life.
Hydraulic Oil Filtration Systems Extend Equipment Life and Cut Downtime
Hydraulic oil filtration systems are designed to achieve and maintain proper ISO cleanliness levels. We offer advanced filtration capabilities to efficiently and effectively remove contaminants. Those oil filtration systems include hydraulic filter carts and portable mobile equipment. The portable oil filter carts are compact and lightweight, making them easy to transport and move.
For hydraulic equipment in marine applications, since more than 90% of hydraulic system failures onboard vessels are due to water or fine contaminant particles in the hydraulic oil, it makes sense to maintain the hydraulic fluid rather than the equipment. Water contamination in onboard hydraulic systems is due to leaking seals in systems that come into contact with seawater, such as trustees, stabilizers, propellers, etc.; it is a recognized problem. Fine contaminated particles can come from various sources, such as depleted additives, coatings from tank walls, or metal from normal machinery wear. Better hydraulic oil cleaning is the answer!
How to remove emulsified water from Hydraulic Oil?
Emulsified water is the most dangerous form of moisture contamination because it is chemically dispersed throughout the hydraulic fluid. Unlike “free water,” which settles at the bottom of a reservoir, emulsified water stays in suspension, leading to a milky appearance and a significant drop in the oil’s dielectric strength and load-carrying capacity. To remove it effectively, standard particulate filters are insufficient; you must employ phase-separation technologies that break the chemical bonds between water molecules and oil.
Vacuum Dehydration is widely considered the “Gold Standard” for removing emulsified water. These systems operate by reducing the atmospheric pressure within a vacuum chamber, which lowers the boiling point of water to approximately 130°F (54°C). This allows the water to evaporate without exposing the hydraulic oil to temperatures high enough to cause thermal degradation. This process is highly effective because it removes not only emulsified water but also dissolved water and entrained gases, returning the oil to a “super-dry” state.
For systems with lower viscosity fluids, Coalescing Filtration offers a mechanical alternative to vacuum systems. A coalescing filter uses specialized media, usually fiberglass or synthetic fleece, to capture tiny droplets of emulsified water. As the oil passes through the filter media, these droplets are forced together to form larger, heavier drops. Once these drops reach a certain size, gravity pulls them down into a collection sump where they can be manually or automatically drained, leaving the clean hydraulic oil to return to the system.
Maintaining water-free hydraulic oil requires proactive monitoring using Moisture Sensors and regular lab analysis (ASTM D95). While vacuum dehydration and coalescing filtration are reactive solutions, the best strategy is prevention. Using desiccant breathers on reservoirs can stop moisture from entering the system through the air intake. By combining high-efficiency particulate filtration with dedicated water removal technologies, you can extend the life of your hydraulic components, significantly reducing unplanned downtime and hydraulic oil replacement costs.
Summary of Removal Methods
| Method | Best For... | Key Advantage |
| Vacuum Dehydration | Large volumes, high-precision systems | Removes dissolved, emulsified, and free water. |
| Coalescing | Low viscosity, mineral oils | Lower cost than vacuum; continuous operation. |
| Centrifuge | Massive water contamination | Rapidly separates water via G-force. |
| Absorptive Filters | Small systems | Uses "super-absorbent" polymers to soak up water. |
Top Full-Flow Hydraulic Oil Filtration Brands
Kaydon Filtration
Kaydon Filtration, a Filtration Group company, is a global leader in oil filtration and conditioning. Kaydon specializes in high-performance liquid and solid separation technology. Kaydon is a designer and manufacturer of filtration systems and equipment. They manufacture filter housings, filter cartridges, portable hydraulic filter carts, and complete filtration systems for the marine, power generation, and mining industries. Kaydon Filtration offers advanced oil filtration solutions designed for fluid conditioning, particulate removal, and coalescing filtration.
The Kaydon KP Series has an ISO 4406 cleanliness code of 17/15/13. Kaydon hydraulic filtration solutions, paired with high-quality filter elements, deliver superior contaminant removal and extended equipment life.
Top Centrifugal Separation Brands
Alfa Laval Separators
Alfa Laval is a renowned leader in centrifuge and separation technology, known for delivering innovative, high-performance solutions across a wide range of applications. To learn more about refurbished Alfa Laval separators, visit our reconditioned Alfa Laval Separators webpage.
GEA Westfalia Separators
GEA Westfalia is a global leader in separation technology. GEA Westfalia self-cleaning separators efficiently treat lube oil, ensuring long-lasting engine protection. As a market leader in separation equipment, GEA Westfalia provides reliable, high-performance solutions.
Learn more about GEA Westfalia OSD 2-02-137, OSE eagleclass, and OSF marine separators.
IOW Group
IOW Group is a leading manufacturer of centrifugal filters. They are well known for their high-quality centrifugal filtration products and updated centrifuge filter design. Unlike the Alfa Laval and GEA Westfalia centrifuges, the IOW centrifugal bypass separators are driven by engine oil pressure (or by an external pump). IOW Group centrifuges utilize bowl-disc technology (for improved separation efficiency) and remote monitoring (for better control). To learn more about the high performance of the IOW filtration centrifuges, visit the IOW Group centrifugal bypass filter.
For more information, visit The Comprehensive Guide to Hydraulic Oil Cleaning.
Hydraulic Oil Filtration You Can Trust for Clean, Reliable Power.
Separator Spares & Equipment is committed to providing cost-effective hydraulic oil filtration systems that will positively impact your business. Hydraulic oil cleanliness and particulate contamination control are crucial components of a proactive maintenance strategy. We can assist with hydraulic oil filtration products, solutions, and expertise. We offer a broad range of oil filtration products for industrial fluids designed to remove particles, water, varnish, and other contaminants. Our cost-effective hydraulic oil filtration systems will lower maintenance costs (thereby reducing total cost of ownership), increase reliability, and reduce energy consumption.
Don’t wait for your hydraulic fluid to turn milky. Implementing a side-stream (kidney loop) filtration system allows for continuous water and particulate removal without interrupting your machine’s operation. Explore our Industrial Oil Filtration Solutions here.
Keeping your hydraulic fluid clean is the key to maximizing oil life and protecting your valuable hydraulic equipment. Our hydraulic filtration products, including high-performance hydraulic filters and precision-engineered filter elements, deliver the reliability your systems demand. By adding offline filtration to your setup, you ensure continuous cleaning and a clean fluid even when your equipment is not in operation. With our advanced hydraulic filtration solutions, you will extend oil life, cut maintenance costs, and keep your equipment running at peak performance.
Do you need any spare hydraulic filter parts for your hydraulic fluid filtration system? Separator Spares & Equipment specializes in genuine and compatible filter spare parts, including filter elements, housings, replacement filter carts (offline filtration), and accessories for every application. We are committed to delivering the right solution and reliable oil filtration solutions that cut maintenance costs and minimize downtime.
Hydraulic Oil Filtration Systems | Solutions, Service, and Expertise