ISO 16889 PDF

ISO HYDRAULIC FLUID POWER – FILTERS – MULTI-PASS METHOD FOR EVALUATINGFILTRATION PERFORMANCE OF A FILTER ELEMENT. Introduction. The obsolescence of AC Fine test dust (ACFTD) has led to the adoption of a new test dust, ISO Medium Test. Dust (ISO MTD), and the impending. ISO Multi-Pass Test. The multi-pass test is a means of determining a filter’s performance; it measures the ability of the filter to remove particles of test dust.

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The data that can be made available is as follows:. The changes in the ISO multi-pass test method and associated standards provide greater precision in measurement. The current data requirement is a substantial improvement.

If the filter fails to provide the necessary control of damaging-sized particles, then their presence in the system will lead to a substantial increase in the number of particles generated within the system through a chain reaction of wear.

This will ieo through the larger pores in isso medium and any holes created by poor manufacturing techniques. It is able to control the critically sized particles better than Element B. The Best Gets Better: It is only when the ratings at higher Beta ratings are considered that the differences in performance are clearly seen.

Current Issue Archive Advertise. This gives a series of Beta ratios for the filter ieo opposed to a percentage efficiency. Figure 2 shows the advantages of this approach.

However because of particle count statistics in the multi-pass test, the absolute rating cannot be measured with any degree of confidence. The need to remove particles consistently across a wide size range was recognized by the ISO Working Group responsible for updating the multi-pass filter test. The more critical the system, the stronger the filter element and the more frequent the monitoring required.


The Role of the Filter To appreciate the importance of the filter in the management of the system, consider the primary function of the filter: In the s and s, a compromise was reached between what is desirable and what can be consistently achieved for the range of filters assessed by this test.

A filter must control the levels of all contaminant particles at and above the size critical to its operating system.

Clarifying the New ISO Contamination Filtration Standards

About the Author Mike Day. What value is most appropriate? Create your own user feedback survey.

It has to protect the components from the damaging, critical clearance-sized isso particles that can penetrate and interfere with the working clearances of components.

This uso essential to achieve the required system reliability and life. Additionally, the user can have greater assurance and confidence in the data, and designers or specialists can make a more informed judgment in the selection of the most appropriate filter for his system.

Therefore, the desired level of control will not be achieved. The Beta ratio is defined as: It is a preselection requirement that provides the user and specifier of filter standards with more consistent information.

This demands care in the selection of the most appropriate filter for the system.

Clarifying the New ISO Contamination Filtration Standards

Users of filters have historically liked the simplicity of 18689 single point rating the size where a specified Beta ratio is attained. This makes the capture of these particles, by the filter, essential to sustain the good health iwo the system. Users were often confused when comparing performance data of seemingly identical filters. It should allow fluid to pass through at the given flow with the minimum pressure drop DP to minimize stress and energy losses.


Most manufacturers published ratings at other sizes but there was no consistency.

The group also stipulated that detailing comprehensive performance data was necessary so users can make informed selections. The Beta ratio is defined as:.

This article will focus on the impact the new standards have on selecting candidate filters based on performance criteria. Therefore, the highest Beta ratio that can be reliably measured should be selected. While primarily developed for fluid power, the new standards are equally applicable to the lubricating oil sector.

Strategies lso Protect Grease Fittings from Contaminants. The slope 16898 the curve effectively defines the pore size distribution PSD of the filtration medium; the wider the PSD the less able the filter is to control those critically sized damaging particles. Toggle navigation Toggle search. When the contaminated hydraulic fluid passes through the filtration medium, it takes the line of least resistance. The data that can be made available is as follows: To appreciate the importance of the filter in the management of the system, consider the primary function of the filter: It also enables the user to discriminate between elements that achieve the desired control and those that do not.

Now, is can quickly see how the filter performs over a specified range of particle sizes and can compare the performance of candidate elements. The effectiveness of the hydraulic filter to control clearance-sized particles is essential if the desired level of reliability is to be realized in the hydraulic system concerned. Particles entering component working clearances will become work hardened and produce more wear particles.