Compressed air system components and piping introduce water, oil, metal, desiccant fines,and other contaminants to the compressed air. Compressed air filters remove these contaminants from compressed air systems.

How compressed air filters prevent compressed air system damage
Compressed air filter applications and schematic
About Particulate Filters and Coalescer Filters
Product info and Literature links
Condit sells and services Pneumatic Products line of filters. Pneumatic Products manufactures premium high quality compressed air filter elements including replacement coalescer and particulate filters. Products include...

• Particulate compressed air filters designed for use downstream of desiccant dryers in compressed air systems. The filter elements provide low pressure drop and 0.9 micron absolute filtration
• Coalescer filters designed to remove liquid aerosols (water and oil) from compressed air and gas streams.
• Select Series particulate filters and coalescer filters are high quality cost-effective filters for critical process air applications

Applications

1. Particulate filter upstream of the coalescer filter reduces the load on the more expensive coalescer filter.
2. Coalescer upstream of the desiccant compressed air dryer protects the dryer from liquid water and oil.
3. Particulate filter downstream of the desiccant compressed air dryer removes desiccant fines and other hard particulate protecting system components from abrasive wear.

About Compressed Air Filters

Installed downstream of desiccant compressed air dryers particulate filters remove desiccant fines. The vast majority of these desiccant fines are 1 um and larger. Our standard particulate filters use pleated epoxy coated cellulose media. The filter media acts as a physical barrier trapping desiccant fines on the downstream side and allowing clean compressed air to pass. Over the life of the filter a filter cake forms. The fines and other contaminants form a sieve on top of the filter increasing the filter's dirt holding capacity.

Less effective filtration technology used as particulate filters include molded and wound filter cartridges. These less expensive filters do not offer the same protection as pleated particulate filters. Both wound filters and molded filters have shorter service lives than pleated filters and offer less efficiency. Wound and Molded particulate filters leave your system exposed to more contaminants and therefore greater abrasive wear.

High temperature particulate filters have a pleated glass fiber media. The glass fiber can withstand the torturing 450° heat downstream of heat reactivated desiccant compressed air dryers during regeneration.

Particulate filters are also often used upstream of more expensive coalescer filters. Coalescer filters remove water from the compressed air stream protecting desiccant compressed air dryers from liquid water. By installing a particulate filter before a coalescer filter you allow the particulate filter to capture fines and other hard contaminants reducing the load on the coalescer. In essence the coalescer does not have to do double duty as a pre-filter and coalescer with a particulate filter installed upstream.

Coalescer Filters

Coalescer filters drain liquid aerosols from the compressed air stream. Located upstream of compressed air dryers coalescer filters stop liquid aerosols and coalesce them into larger droplets, which drain off the filter media by gravity. The water and oil droplets collect in the filter housing sump and an automatic drain valve is used to remove the condensate from the compressed air system.

The purpose of locating the coalescer filter upstream of the desiccant air dryer is to remove liquids, which the compressed air dryer is unable to remove. Coalescer filters prevent erosion and clogging of the air system and protects the desiccant from liquid fouling.