Coalescing Filters

A coalescing filter is a device used to separate vapours, liquids, soluble particles, or oil from some other fluid through a coalescing effect.

The coalescing effect is the coming together of liquid aerosols form a larger whole which is easier to filter out of the system due to increased weight.

The filter consists of several progressive layers which perform specific functions; from separating solid particles to liquid molecules from a gas flow.
Some common materials used as coalescing filters include borosilicate microfibers and semi-permeable membranes.
Coalescing filters should always flow from the inside of the filter element to the outside of the filter element. This allows for the oil and water droplets to collect on the fibres of the filter element and meet at crossover points and become larger and larger droplets (the process of coalescing) as they travel downward and outward to the base of the filter element. The large droplets drop off the base of the filter element into the sump area of the filter housing and ultimately into an automatic float drain where the liquids are drained out of the system.