Since all atmospheric air contains some water vapor and particulate matter, all compressed air systems contain concentrated volumes of moisture and contaminants.

To remove moisture and contaminants from a compressed air system, the following equipment should be used:

Aftercoolers are a necessary first step in compressed air treatment. They lower the compressed air temperature to acceptable inlet conditions for air dryers, and remove up to 70% of the entrained water vapor. Depending on site conditions and utilities, aftercoolers are available in water-cooled or air-cooled configurations. Where water and electric are not available, air cooled aftercoolers with air driven motors are available.

Air dryers are used to lower the dew point temperature of compressed air, further reducing the amount of water vapor remaining in the process airflow. If applied correctly, a compressed air dryer should eliminate the possibility of liquid water forming in any downstream piping. Refrigerated air dryers lower dew point by reducing the actual air temperature to near freezing conditions, causing moisture to condense from the air. Once the water is removed via centrifugal action, the air is reheated to a usable temperature. Desiccant air dryers use the chemical adsorption method of drying and can typically achieve dewpoints as low as -100^oF.

• Coalescing filters collect and extract liquid water and oil.
• Particulate filters trap unwanted solid contaminants.
• Adsorbing filters soften odors and polish compressed air.
• Separators & drains remove collected liquids and are used in various locations throughout an air system.