FILTER PLUGGING TENDENCY OF DISTILLATE FUEL OILS: ASTM D2068
EXPLANATION
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. A change in filter performance after storage or pretreatment can be indicative of changes in fuel condition. This test method is intended for use in evaluating distillate fuel cleanliness in those applications that demand a high throughput per installed filter. This test method is applicable to fuels within the viscosity range of 1.50 to 6.00 cSt at 40° C. This test method is not applicable to fuels that are not clear and bright because water interferes with the measurement of filter plugging. Relative tendency of fuels to plug filters may vary depending on filter porosity and structure, and may not always correlate with the results from this test method.
TEST SUMMARY
A sample of fuel is passed at a constant flow rate 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. The apparatus is required to be calibrated at intervals.
TEST PRECISION
This test method has a repeatability of 0.27 FPT-1 and a reproducibility of 1.405 FPT-1 where FPT is the normalized result.
This test method has no bias.
