Definition - What does Set Point mean?
Set Point, also known as pour point is the temperature at which a liquid becomes semisolid and loses its flowing characteristics. Crude oil has a high pour point due to high content of paraffin and it begins to precipitate when the temperature is lowered down to a certain level. However, oils or synthetic fibers that have high set point suffer from severe screening effect and excessive pressure. The temperature at which the liquid ceases to pour can be determined by ASTM D-97 pour point test.
Petropedia explains Set Point
Set Point is seen in oil that is a derivative of kerogen II. There are two main methods used to detect the set point of a liquid, i.e., manual and automatic method. Crude oil has two pour points that give an approximate value of the temperature window based on the thermal history. The upper pour point can be calculated by pouring the liquid directly into the test jar whereas the lower pour point can be measured by pouring the sample into a pressure vessel made up of stainless steel. As fluids lose viscosity and fluidity at a higher temperature, pour point depressants are added which allow the mineral oils to work efficiently.