ASTM D6824 Standard Test Method for Determining Filterability of Aviation Turbine Fuel
4. Summary of Test Method
4.1 A sample is passed at a constant rate (20 mL/min) through a standard porosity filter medium. The pressure drop across the filter and the volume of filtrate are monitored. The test is concluded either when the pressure drop across the filter exceeds 104 kPa (15 psi) or when 300 mL have passed through the filter.
4.2 Results are reported as either the volume that has passed through the filter when a pressure of 104 kPa (15 psi) has been reached or the pressure drop when 300 mL have passed through the filter.
4.3 Verification of the apparatus is required when there is a doubt of a test result, or when the apparatus has not been used for three months or more. It is not necessary to verify apparatus performance prior to each test.
5. Significance and Use
5.1 This test method is intended for use in the laboratory or field in evaluating aviation turbine fuel cleanliness.
5.2 A change in filtration performance after storage, pretreatment, or commingling can be indicative of changes in fuel condition.
5.3 Relative filterability of fuels may vary, depending on filter porosity and structure, and may not always correlate with results from this test method.
5.4 Causes of poor filterability in industrial/refinery filters include fuel degradation products, contaminants picked up during storage or transfer, incompatibility of commingled fuels, or interaction of the fuel with the filter media. Any of these could correlate with orifice or filter system plugging, or both.
