Oil contamination is often recognized as the leading cause of downtime in industrial environments. Contamination can reduce equipment performance and lifespan, causing unplanned maintenance and lost productivity. In these situations, people often overlook one critical component. 

The filter element is the heart of your filtration system. As oil flows through it, it should capture and retain the contaminants that can harm your equipment. But sometimes even a new filter has issues maintaining clean oil. 

If you're experiencing unstable ISO cleanliness codes, short filter life, or changing differential pressure, it may be time to consider the quality of your filter elements. 

Consider Filter Efficiency and Real-World Performance

High-efficiency filters can capture more contaminants, keeping oil cleaner, reducing component wear, and helping maintain stable ISO cleanliness codes.

Filter performance is often represented using a Beta Ratio, which measures how effectively a filter removes particles of a specific size in a single pass under controlled laboratory conditions. 

On the chart below, you can see different beta ratio efficiencies along with how many particles are coming into the filters (upstream) and how many particles may be allowed to pass through (downstream).

Some filters are tested using ISO 16889 multi-pass methods. These tests measure performance over repeated passes of contaminated oil. This helps you see how a filter could perform over time.

However, real hydraulic systems experience startups, shutdowns, and fluctuating flow that can cause a filter to shed captured particles. Dynamic Filter Efficiency (DFE) evaluates particle capture and retention during flow fluctuations and start-stop cycles. DFE can help show which filters maintain cleaner oil in operating conditions closer to the real world. 

Researchers first developed the DFE test method in 1998 from a joint effort by Scientific Services Inc (SSI) and Hy-Pro Filtration.

Consider Long-Term Value

A common misconception is that high-efficiency filter elements wear out faster. In reality, when a filter effectively captures and retains contaminants, overall filter and component life can increase.

When contamination circulates through a hydraulic system, it contributes to abrasion. This generates additional particles, increasing overall contamination levels and ISO codes, and accelerating wear on system components. 

In short, contamination leads to more contamination. Dirt makes dirt. Consider the beta ratio comparison chart and the abrasion that can happen when a large number of particles are allowed to pass downstream.

To break this cycle, high-efficiency filter elements must capture and retain particles. When less particulate matter circulates through the system, you can achieve fewer filter changeouts, improved reliability, and better long-term filtration value. 

For example, a Donaldson Hy-Pro case study showed a high-production copper mine saved nearly $500,000 in one year after switching to Donaldson Hy-Pro filter elements. These savings resulted from reduced pump replacements, lower oil consumption, and fewer filter changeouts.

When evaluating hydraulic filtration systems, filter performance should always be a key consideration.

Support Your Operational Goals

Is your goal to protect your equipment, reduce waste, and experience fewer unplanned shutdowns? Filter element selection is one of the most important steps toward more reliable operations.

Checklist for Choosing the Right Filter

Answer these questions to help ensure your filtration decisions align with your reliability goals. 

• Efficiency & Particle Capture: Does the filter effectively remove particles? Check ISO cleanliness levels against your target codes before and after a filter change. Look for high-efficiency media suited to your contamination levels.

• Performance: Has the filter been tested for dynamic conditions to help ensure it retains particles during flow fluctuations, startups, and shutdowns? 

• Filter Construction & Compatibility: Is the element designed for your housing, bypass configuration, and downstream components? Proper media and construction ensure the filter performs as intended under system pressures and flows. Poor fit, weak media, or misalignment can reduce efficiency, cause bypassing, or release particles back into your system.

• Service Life & Retention: Does the filter capture and hold contaminants without shedding, minimizing unplanned changeouts and maintenance? 

• Total Cost of Ownership: Consider replacement frequency, oil savings, labor, and disposal costs.

Frequently Asked Questions

Q: Are all hydraulic filter elements the same?

A: No. Differences in media efficiency, construction, and particle retention performance can significantly affect oil cleanliness and component life. Higher-efficiency elements with DFE testing can help maintain better ISO cleanliness levels and reduce the risk of premature component failure.

Q: How do I choose the right filter for my system?

A: Identify your main contaminants (dirt, water, or varnish) and consider your system’s operating conditions. Contact Donaldson Hy-Pro experts for help finding a solution unique to your situation. 

Q: Is lab-tested efficiency enough?

A: Not always. Real operating conditions like fluctuating flow, pressure, and contamination affect performance. Filters tested for dynamic conditions can provide additional information.

Q: Will higher-efficiency filters wear out faster?

Not necessarily. Efficient filters can capture contaminants better, extend service intervals, and reduce unexpected changeouts.

Q: How does filter choice affect cost?

A: The right filter can reduce downtime, extend oil life, and minimize disposal. Evaluating total cost of ownership gives a clearer picture of filter element value.

About Donaldson Hy-Pro:

Donaldson Hy-Pro offers a wide range of hydraulic filtration solutions that can help you improve the performance of your machinery. Our filter elements are designed to combat dirt, water, and oxidation by-products, to help keep your systems running at peak performance.

If you're looking for a way to reduce filter expenses, improve oil cleanliness, and extend the life of your equipment, Donaldson Hy-Pro can help. Contact us today to learn more.