EXPLANATION
When a lubricating grease separates oil, the residual material changes in consistency which can affect the ability of the product to function as designed. Test results obtained with this procedure are intended to correlate with oil separation that occurs in 35 lb pails of grease during storage. They are not untended to predict oil separation tendencies of grease under dynamic service conditions. No quantitative relationship between results and oil separation in 35 lb pails have been developed. No data have been developed to compare results between this test method and Test Method ASTM D1742 Oil Separation from Greases During Storage.
The conical sieve method for measuring leakage from lubricating grease (commonly known as the cone bleed test) is virtually the same as Federal Test Method 791C Method 321.3. The test method is conducted at 100° C for 30 h unless other conditions are required by the grease specification. This test method is not suitable for greases having a penetration (Test Method ASTM D217) greater than 340 (softer than NLGI No. 1 Grade).
TEST SUMMARY
A weighed sample is placed in a cone shaped, wire-cloth sieve, suspended in a beaker, then heated under static conditions for the specified time and temperature. Unless otherwise required by the grease specification, the sample is tested at standard conditions of 100 +/- 0.5° C for 30 +/- 0.25 h. At the end the separated oil is weighed and reported as a percentage of the mass of the starting test sample.
TEST PRECISION
Where M is the mean of two determinations. The values above are expressed as % oil separation.
This method has no bias because the value of the oil loss is defined only in terms of this test method.