ASTM D2386 – Freezing Point of Aviation Fuels
Aviation fuel is typically a mixture of hydrocarbons. When aircrafts are exposed to cold temperatures, either on the ground or in flight, some of these hydrocarbons may begin to crystallize (freeze), potentially clogging fuel filters, limiting fuel flow and engine efficiency. The freezing point, which is determined in this test, is the lowest temperature at which the fuel remains free of hydrocarbon crystals.
The sample is placed in a sample tube, immersed in a cold bath and allowed to cool while being observed and manually stirred. When crystals begin to form, the sample is gradually warmed and the temperature at which the crystals disappear is reported as the freezing point.