![]() ![]() It follows a double logarithmic function.Ī low VI expresses a considerable change of viscosity with change of temperature. Furthermore, the viscosity change over temperature is not linear. Additional influences such as oxidation, contamination, and pressure during operation have an impact on the viscosity. To compare SUS (ASTM D88) with mm²/s, an online calculator, such as the Anton Paar calculator for ASTM D88 / Saybolt universal viscosity can be used.Ĭompared to water, which has nearly the same flow behavior over a wide temperature range, oil changes its viscosity significantly with changing temperature. Today, the kinematic viscosity in mm²/s is used for the VI calculation. Initially, the viscosity was measured in Saybolt Universal Seconds (SUS). Today, temperatures of 40 ☌ and 100 ☌ are common. The Fahrenheit temperature scale is still frequently used in the Anglo-American area. In the early VI systems, the temperatures for viscosity measurement were 100 ☏ and 210 ☏, corresponding to 37.78 ☌ and 98.89 ☌. To increase the VI to values higher than 100, new base oil types and special additives were developed later on. In the middle, a VI of around 50 would be assigned. ![]() If the oil was similar to the paraffinic oil, a VI of 100 was assigned if it was similar to the naphthenic oil, a VI of 0 was assigned. Lube oils were then compared to these benchmarks. Their VI was indicated with 0 – this was the worst possible VI. Oils with significant viscosity change (LVI-oils, refined from Texas gulf crudes, naphthenic oil) represented the low end. Their VI was indicated with 100, which represented the best VI. Oils with low temperature-dependent viscosity change (HVI-oils, refined from Pennsylvania crudes, paraffinic oil) were on the high end of the scale. For the VI scale, two limit points were set. At this time, no multi-grade oils and no synthetic oils were available. For this purpose, the viscosity index 12 for base stocks and lube oils was developed by Dean and Davis from Standard Oil in the year 1929. For any oil used under changing temperature conditions, it is important to know the change of viscosity in relation to the change of temperature. Temperature is the most influential parameter for the viscosity change of oil. However this work has demonstrated the feasibility of using groundnut oil as a hydraulic fluid.The viscosity of lube oil does not give any relevant information unless the temperature, at which it was measured, is known. The low temperature flow property (pour point) is the only result that does not meet ISO specification with-3 o C but can be handled by addition of cold flow property depressant (additive). The result showed a good peroxide value and iodine value from oil sample. The flash point (249.1 o C), the fire point (255.2 o C), acid value (0.3942mg (KOH)/g) all exceed the ISO specification. The result showed that the viscosity at 40 o C and 100 o C are 34.1mm 2 /s and 7.08mm 2 /s which exceeded the international standard organization (ISO) specification of (12-100) mm 2 /s and 5mm 2 /s for 40 o C and 100 o C respectively. The key steps will be to experiment the viscosity of groundnut oil at 40 o C and 100 o C respectively, specific gravity, viscosity index, acid value, Pour point, flash point, fire point, peroxide and iodine value using refined groundnut oil as sample. Benchmark tests and experiment were carried out to ascertain the physio-chemical property of groundnut oil. This study is set out to ascertain the suitability of groundnut oil as a hydraulic fluid. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |