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Glossary

Glossary

Kinematic Viscosity :

Kinematic viscosity characterizes the speed at which a fluid flows from Point A to Point B at a given temperature. The reference temperatures are 40C and 100C.

ISO viscosity is expressed in square millimetres per second (mm2/s), at 40C or 100C.

Viscosities have been ISO standardized (International Standard Organisation). The ISO grade enables tolerance of +/- 10% with respect to the reference value.


Viscosity Index (VI) :

Viscosity is affected by changes in temperature. Viscosity drops when the temperature increases. And inversely, viscosity increases when the temperature drops.

At a high temperature, viscosity must be sufficient enough to form a lubricant film. At a low temperature, viscosity must not be too high, as the lubricant must run and be pumpable.

The Viscosity Index defines the relationship between viscosity and temperature.


Flash Point (FP) :

This is the temperature at which the most volatile oil vapours ignite briefly when in contact with a flame. The temperature is not high enough for combustion to self-sustain.


Fire Point (ignition point) :

Temperature at which the most volatile oil vapours ignite when in contact with a flame and continue to burn. Combustion begins.


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