- Method ASTM D4870
- Repeatability Variable, see method
- Reproducibility Variable, see method
- Blending non-linear
- Additive Correction No
The purpose of this test is to determine total sediment up to 0.40% m/m in residual fuel oils having a maximum viscosity of 55 cst (mm 2/S) at 100C. There are some fuels that may exceed the maximum filtration time specified in this method due to factors beyond the presence of significant quantities of insoluble organic or inorganic material. The method may be used for the assessment of total sediment after regimes of fuel pretreatment designed to accelerate the aging process.
This method is performed by first starting the heating process on the filtration unit while conditioning filters. Once the filters are conditioned they are weighed and placed on the instrument. Next a beaker containing the residual fuel to be analyzed is weighed. The vacuum is then started and the fuel oil is filtered. One the fuel has passed through the filters they are rinsed with trisolvent to remove any fuel that is left so only sediment remains. The filters are then dried, cooled, and weighed. The sediment result is calculated as part of the whole sample.
An excess of sediment contained in residual fuels can cause many issues. Sediment can obstruct filters in pumps causing burner and engine systems to fail. It can also accumulate on the bottom of storage tanks and cause issues with transfer pumps.