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

Clarifying the New ISO Contamination Filtration Standards

It also enables the user to discriminate between elements that achieve the desired control and those that do not. Particles entering component working clearances will become work hardened and produce more wear particles.

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.

Figure 2 shows the advantages of this approach.

Hydraulik├Âl-Filtrationssysteme | Donaldson Hydraulik

About the Author Mike Day. The current data requirement is a substantial improvement. It should allow fluid to pass through at the given flow with the minimum pressure drop DP to minimize stress and energy losses. The slope of the curve effectively defines the pore size distribution PSD of the filtration 166889 the wider the PSD the less able the filter is to control those critically sized damaging particles.


The filter should control the fluid cleanliness to a level that is equal to the performance, life and reliability of the system required by the user. The Beta ratio is defined as:. It is able to control the critically sized particles better than Element B. This gives a series of Beta ratios for the filter as opposed to a percentage efficiency.

The data that can be made available is as follows:. However, the multi-pass test is carried out in a laboratory under steady-state conditions and does not represent strenuous operational conditions. What value is most appropriate? To appreciate the importance of the filter in the management of the system, consider the primary function of the filter: The data that can be made available is as follows: It is only when the ratings at higher Beta ratings are considered that the differences in performance are clearly seen.

Clarifying the New ISO Contamination Filtration Standards

The Beta ratio is defined as: Create your own user feedback survey. The changes in the ISO multi-pass test method and associated standards provide greater precision in measurement. The more critical the system, the stronger the filter element and the more frequent the monitoring required.

A filter must control the levels of all contaminant particles at and above the size critical to its operating system. 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: Most manufacturers published ido at other sizes but there was no consistency. The Best Gets Better: 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.

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It is a preselection requirement that provides the user and specifier uso filter standards with more consistent information.

Therefore, the highest Beta ratio that can be reliably measured should be selected. However because of particle count statistics in the multi-pass test, the absolute rating cannot be measured with any degree of confidence.

Strategies to Protect Grease Fittings from Contaminants. Current Issue Archive Advertise. Therefore, the is level of control will not be achieved. Toggle navigation Toggle search. More detailed information from the test has to be published than previously required.

This will be through the larger pores in the medium and any holes created by poor manufacturing techniques. Consequently, the number of different Beta ratings used has proliferated.

When the contaminated hydraulic fluid passes uso the filtration medium, it takes the line of least resistance. It has to protect the components from the damaging, critical clearance-sized particles particles that can penetrate and interfere with the working clearances of components.

This is essential to achieve the required system reliability and life. The group also stipulated that detailing 166889 performance data was necessary so users can make informed selections. These standards have been developed to increase the precision in the measurement of contamination and filtration performance, and to extend the amount of information from the tests.