ASTM D6795 Standard Test Method for Measuring the Effect on Filterability of Engine Oils After Treatment with Water and Dry Ice and a Short (30 min) Heating Time
4. Summary of Test Method
4.1 The test oil is treated with deionized water and dry ice. The sample is heated to 70 °C for 30 min, followed by storage at room temperature. The sample is filtered and the flow rate is calculated determining the engine oil filterability characteristics.
5. Significance and Use
5.1 It is normal for some of the combustion products of an internal combustion engine to penetrate into the engine lubricant and be retained in it.
5.2 When an engine is run for a period of time and then stored over a long period of time, the by-products of combustion might be retained in the oil in a liquefied state.
5.3 Under these circumstances, precipitates can form that impair the filterability of the oil the next time the engine is run.
5.4 This test method subjects the test oil and the new oil to the same treatments such that the loss of filterability can be determined.
5.5 Reference oils, on which the data obtained by this test method is known, are available.
5.6 This test method requires that a reference oil also be tested and results reported. Two oils are available, one known to give a low and one known to give a high data value for this test method.
NOTE 1 - When the new oil test results are to be offered as candidate oil test results for a specification, such as Specification D4485, the specification will state maximum allowable loss of filterability (flow reduction) of the test oil as compared to the new oil.
