Calculating viscosity index iso#

A holistic approach to lubricant analysis Most lubricants offer Vis ranging from between 90 to 160, though some can be as low as -60 or as high as 400. Today, ASTM D2270 Standard Practice for Calculating Viscosity Index from Kinematic Viscosity at 40 ☌ and 100 ☌ is one of the most widely used methods to calculate VI. Viscosity Index helps operators make informed decisions to prepare for these changes and minimise the risk of unplanned downtime. Temperature changes can and do occur, triggered by anything from weather patterns to mechanical overheating. VI allows operators to compare how different lubricants behave when exposed to temperatures outside normal operating conditions. This is usually a mistake as VI can have a big impact on how a lubricant performs when in circulation and exposed to temperatures other than the standard 40☌ used to calculate viscosity. Why Viscosity Index mattersĪs mentioned earlier, Viscosity Index is often disregarded during the lubricant selection process. A higher VI number indicated more stability when exposed to temperature changes. Pennsylvania crude was given a VI of 100 while Texas Gulf crudes were given a VI of 0. Using Pennsylvania crude as a benchmark for low viscosity and Texas Gulf crudes for high viscosity, the team developed a method for calculating changes in internal resistance to flow relative to temperature.

$calculating viscosity index$

The concept of Viscosity Index was first developed in the 1920s by a pair of American chemists. VI is an independent parameter and is used to calculate how viscosity will change when exposed to temperatures higher or lower than 40☌.

Calculating viscosity index iso#

Viscosity Index vs ISO Viscosity GradeĬontrary to popular belief, Viscosity Index is not part of ISO Viscosity Grade, which calculates viscosity at a standard temperature of 40☌. While VI is often an overlooked parameter when selecting lubricants, it can offer valuable insight into how the lubricant will behave when in use.

Temperature-triggered changes in the viscosity of a lubricant is known as Viscosity Index (VI). However this work has demonstrated the feasibility of using groundnut oil as a hydraulic fluid.Viscosity can vary enormously between different lubricants and temperature often plays a key role in changing internal resistance to flow. 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. A high viscosity index ensures consistent lubricating properties across a. The higher the viscosity index, the lower the viscosity change of an oil at fluctuating temperatures. Benchmark tests and experiment were carried out to ascertain the physio-chemical property of groundnut oil. The viscosity of oils and base oils of lubricating greases from Klüber Lubrication can be determined by means of the known kinematic viscosity at 40 ☌ and 100 ☌. This study is set out to ascertain the suitability of groundnut oil as a hydraulic fluid.