Anti emulsification ability (demulsification ability) refers to the oil-water separation ability of lubricating oil, which is important for turbine oil and the service life of the oil. In the experiment, oil and water were mixed in a 1:1 ratio. 40 milliliters of turbine oil and 40 milliliters of distilled water were taken, stirred, and left to stand for observation of oil-water separation. The time required for complete separation of the oil-water layer (also known as demulsification time) was recorded. The shorter the time, the better the oil-water separation ability of the oil.
Although ASTM D standard does not provide a warning value for anti emulsification, for oil in use, if the volume of the emulsion is ≥ 15 milliliters after 30 minutes, the anti emulsification performance of the oil is already poor. For new oil, the remaining emulsion volume after 30 minutes should be less than 3 milliliters. Oil contamination, long-term storage, and oxidation can cause a decrease in anti emulsification properties.
The residence time of turbine oil in the oil tank has an impact on the oil-water separation of the oil. If the oil tank is small, the shorter the demulsification time of turbine oil is required. For large fuel tanks, the allowed demulsification time can be longer. That is to say, if the fuel tank is small, the requirement for anti emulsification is higher.
Anti emulsifying properties should be tested once a year, and if in frequent contact with water, the testing cycle should be shortened.