BS ISO 18413:2015 pdf download – Hydraulic fluid power — Cleanliness of components — Inspection document and principles related to contaminant extraction and analysis, and data reporting.
6.3.2.3.5 When an extraction method is applied to several components due to their low level of contamination (e.g. in relation to the value of the blank level), it is not necessary to measure the contamination level of the extraction sample from each component. In this case, the liquids from all extractions shall be mixed and analysed as specified in Clause 7, provided that the concentration of contaminant does not affect the analysis method chosen. 6.4 Agitation 6.4.1 Contaminant extraction by agitation is best suited to hollow components with characteristics (weight, size) allowing them to be hand shaken by an operator or agitated by an appropriate mechanical device. See Table 1 for examples of its application. 6.4.2 Contaminant contained within simple enclosed surfaces shall be removed by partially filling the component under the test with an appropriate test liquid, sealing the openings, and agitating the component to remove the contaminant from the controlled surface and to suspend the contaminant in the test liquid. Immediately after agitation, all extraction liquid used in the test shall be drained and collected for analysis. Annex A provides additional information. 6.4.3 Primary process variables to be controlled include: test liquid and its relevant properties, test liquid volume and temperature, type and duration of agitation, the number of samples extracted up to and including the end-point sample, and the volume of test liquid extracted for analysis. 6.4.4 Consideration should be given to the size and mass of the component, the need for slings or fixtures, and any auxiliary equipment necessary for proper contaminant extraction.
6.5 Pressure rinse 6.5.1 Contaminant extraction by pressure rinsing is best suited to components where the surface to be controlled is easily accessible by a jet of pressurized test liquid. It may be used as a second phase of another extraction procedure such as ultrasonic vibration. See Table 1 for examples of its application. 6.5.2 Contaminant on exposed and accessible surfaces shall be removed by directing a stream of test liquid onto the controlled surface of the component, which is placed over an appropriate liquid collection apparatus. Immediately after rinsing, all test liquid used in the test shall be collected for analysis. Annex B provides additional information. 6.5.3 Primary process variables to be controlled include shape of the jet or nozzle, test liquid and its relevant properties, test liquid pressure and flow rate, test liquid volume and temperature, the sequence followed in rinsing the component, and the number of samples extracted up to and including the end- point sample. 6.5.4 Consideration should be given to the overall accessibility of controlled surfaces for rinsing, the size and mass of the component, the need for slings and fixtures, and auxiliary equipment necessary for proper contaminant extraction.