Particulate air filters provide a first line of defense to remove larger particles of dirt and water from the compressed air in a supply line. These general purpose filters are installed upstream from filters that trap finer particles to prevent premature wear on the more specialized filters.

Coalescing air filters remove oil from the compressed air in a supply line. They are used in applications that require high air quality such as pneumatic conveying systems and paint-spraying tools. A particulate filter is often installed upstream from this filter to remove larger particles and prevent premature wear on these more specialized filters.