Moisture is Always Present in air systems
All air found in the atmosphere contains some water vapor. When the air or gas cools past the saturation point, this water vapor condenses into liquid water in the compressed air system.
The temperature at which the vapor condenses into liquid is known as the dew point. The dew point is important when determining how much compressed air drying is needed.
As equipment evolved, more sophisticated machines were able to use air as a means of power. Not only pneumatic tools use air in a facility but also many other types of machines.
Some of these machines include sophisticated devices and controls that require clean dry air. As a result drying technology advanced, and dryers came into general use.

Moisture may damage the equipment
Moisture in compressed air used in a manufacturing plants may cause problems in the operation of pneumatic tools and increase down time and maintenance as a result.
Among the main problems associated with extreme moisture in air is rust/corrosion which increases the possibility of an air tool to seize and to suffer internal damages and wear.
Pneumatic tools are designed to operate with clean, dry air at the required pressure, usually 90 to 100 psi. Dirty and wet air will result in sluggish operation, more frequent repair and replacement of parts due to sticking, jamming and rusting of wearing parts including ball bearings, rotor blades and so on.
Water also will wash out the air tools oil, resulting in additional and even excessive wear. A decrease in pressure at the tool caused by restricted or plugged lines or parts will cause a reduction in the efficiency of the tool.
Clean, dry air at the required pressure will enable the production worker to start operating immediately at an efficient level, with no time lost to purge lines or drain filters and will help to maintain productivity and prolong tool life.
It is a common practice in manufacturing plants and generally speaking in the industry to use what is known as an FRL (Filter-Regulator-Lubricator) before the air reaches each air tool.
This FRL system allows adjusting the required air pressure per tool as well as essential lubrication. Keep in mind the maximum distance of a hose that will allow for oil to reach the tool is 18 ft. Making sure the fittings do not restrict airflow is very important as well in accordance with the pneumatic tool requirements
