The analysis of changes in total base number and the flash point in the exploited engine oil

This paper is a continuation of the analysis of the grade of wear of the engine oil, used in the Caterpillar's marine engine, which is working in the engine's room of the harbour tug. Previous studies were related to the dynamic viscosity, lubricity and the grade of the metallic elements contamination. In these studies, the viscosity of the oil in most samples decreased with time of exploitation. However, in some samples, an increase of the viscosity was observed, what may indicate the fuel entering into the circulation of lubricating oil and its subsequent evaporation. Aim of this study is to determine the size of the Total Base Number changes and the flash point changes. The authors examine the changes in Total Base Number and the flash point of the exploited engine oil, in specified intervals in time between its exchanges. The results are analyzed and compared to the previously obtained results of the viscosity, lubricity and the grade of the metallic elements contamination. The analyses of the Total Base Number were conducted on the RST 822 Radiometer from Radiometer Analytical A/S, according to the polish standard PN-76/C-04163: Petroleum Products. Determination of the Total Base Number by potentiometric titration with perchloric acid. Flash point was determined using the Cleveland, in the open pot, using an ISL FP 92 5G device from Tusnovics Instruments Poland Ltd. The conclusions of this paper lead to better understanding of the processes, which occur in marine engines and its influence on the oil aging. Understanding of this process contributes significantly to a more accurate mathematical modelling of the aging process of engine oil.