Compressed air supplyA compressed air supply must be available to seal the spindle, supply oil to the bearing orclean the cone. To keep the required air free of contamination and moisture, an air-conditioningunit must be present.The systems which demand compressed-air conditioning are listed in the this section for therespective compressed air quality. This spindle unit does not necessarily contain all systems.Some systems place special demands on the compressed air supply. Compare the data onthe spindle drawing for this.The purity classes are defined according to the ISO 8573-1:2010 standard with the followingreference conditions:● Air temperature 20° C● Absolute air pressure 100 kPa● Relative steam pressure 0