ASTM D2068 Test Method for Filter Plugging Tendency of Distillate Fuel Oils
4. Summary of Test Method
4.1 A sample of the fuel to be tested is passed at a constant rate of flow (20 mL/min) through a glass fiber filter medium. The pressure drop across the filter is monitored during the passage of a fixed volume of test fuel. If a prescribed maximum pressure drop is reached before the total volume of fuel is filtered, the actual volume of fuel filtered at the time of maximum pressure drop is recorded.
4.2 Calibration of the apparatus is required at intervals, and a procedure for the preparation of a fluid for calibration is described in Annex A1.
5. Significance and Use
5.1 This test method is intended for use in evaluating distillate fuel cleanliness in those applications that demand a high throughput per installed filter.
5.2 A change in filtration performance after storage or pretreatment can be indicative of changes in fuel condition.
5.3 Causes of poor filterability might include fuel degradation products, contaminants picked up during storage or transfer, or interaction of the fuel with the filter media. Any of these could correlate with orifice or filter system plugging, or both.
