The wax point is the specific temperature threshold where paraffin waxes present in diesel, kerosene, or heating oil start to precipitate out of the liquid phase. As the fuel cools below this mark, the wax crystals agglomerate and clog fuel filters, lines, and injectors. Refiners manage this property through seasonal blending or by adding cold flow improvers to ensure fuels remain operable in freezing climates.
Heard on the job
We need to dose the winter diesel with flow improvers to drop the wax point before the cold front hits.
Insider tip
Operators often evaluate the cloud point (first visible wax) and pour point (loss of flow) to fully characterize a fuel's wax point behavior.