Answer: According to ISO 8573.1 quality grades, the grade of compressed air treated by the filter is generally divided according to the size of solid pollutant particles, the content of liquid water, and the content of oil droplets, oil mist, and oil vapor after the filter element is treated.
Generally, the grades of filters can be divided into pre-filtration, primary filtration, fine filtration, and activated carbon filtration. Among them, the pre-filter generally removes particles with a diameter of 3~5μm, the primary filter generally removes particles with a diameter of 0.5~1μm and the residual content of oil mist is 1ppm, the fine filter generally removes particles with a diameter of 0.01μm and the residual content of oil mist is 0.01ppm, and the activated carbon filter is mainly used to remove odor and oil vapor (the residual content of oil mist is only 0.003ppm).
