Hydraulic fluid power — Filters — Multi-pass method for evaluating filtration performance of a filter element

This document describes the following:

— a multi-pass filtration performance test with continuous contaminant injection for hydraulic fluid power filter elements;

NOTE 1 For the background interlaboratory study used to verify the test methodology, see Annex D.

— a procedure for determining the contaminant capacity, particulate removal and differential pressure characteristics;

— a test currently applicable to hydraulic fluid power filter elements that exhibit an average filtration ratio greater than or equal to 75 for particle sizes ≥ 25 μm(c), and a final reservoir gravimetric level of less than 200 mg/L;

NOTE 2 It is necessary to determine by validation the range of flow rates and the lower particle size limit that can be used in test facilities.

— a test using ISO medium test dust (ISO MTD) contaminant and a test fluid in accordance with Annex A.

This document is intended to provide a test procedure that yields reproducible test data for appraising the filtration performance of a hydraulic fluid power filter element without influence of electrostatic charge.

This document applies to three test conditions:

— test condition 1, with a base upstream gravimetric level of 3 m