SFD Stands for Separator Filter Dryer. This ingenious design Separator Filter Dryer protects compressed air systems on ready mix concrete batch plants by removing damaging water, oil and other air system contaminants. The SFD is a compact heatless desiccant air dryer that delivers the highest quality air while staying seemlessly easy to maintain. Working continuously, the dryer toggles from one side to the other cleaning the air and regenerating at the same time. So what does this mean for the ready mix concrete industry? Well, concrete companies still rely on compressed air during their winter production. Moisture in the air lines can freeze electric over air valves and bring concrete production to a hault. The SKF SFD solution insures an uninterrupted supply of clean dry air in the ready mix plant. It not only decreases maintenance costs but there's also a significant savings in energy.