System temperatures are important in purging. Changes in temperature cause movement of metal parts (due to the metal’s coefficient of thermal expansion) and this can dislodge contaminants. Increased temperatures enhance the effectiveness of chemical purging compounds by increasing reaction rates.
But the raising and subsequent lowering of temperatures takes time. The positive and negative impacts of changing temperatures must be carefully evaluated in planning a purging process. Manufacturers’ recommendations are a good guide to optimizing temperatures for the purge.