In addition to the dust naturally present in the air, compressed air is also contaminated by oil carried over from the compressor. These impurities can make compressed air unsuitable for further use in many production processes, such as in the food or pharmaceutical industry. It is therefore essential to establish a clear strategy for achieving the required compressed air quality.

Start by installing an intake filter on the compressor and assess whether the type of compressor suits your compressed air needs. Everything that does not enter the compressor does not need to be removed afterwards. To eliminate solid, liquid and even gaseous contaminants, filtration is applied.

Do not overspecify your air quality to avoid unnecessary costs. Filtration fineness is expressed in micrometres [µm] (also called micron or “mu”). 1 µm = 0.001 mm.

Pre-Filter

Filters made of woven, compressed fibres can remove 99.999% of particles larger than approx. 0.3 µm.

The main function of the pre-filter is to extend the service life of the fine filter. They are available with semi-automatic or fully automatic condensate drains.

Ultra-Fine Filters

Also known as coalescing or sub-micron filters. They consist of multiple layers of sub-micron fibre media.

They remove 99.999% of solid particles above 0.01 µm, water droplets and oil mist (aerosols) down to 0.1 µm, ensuring the outlet air contains less than 0.01 mg/m³ of oil content.

Ultra-fine filters must always be used together with a pre-filter.

They must also always serve as the pre-filter for an activated carbon filter to ensure proper performance and long service life.

Activated Carbon Filter

This type of filter contains activated carbon with an extremely fine microporous structure, providing a very large surface area (up to 2,000 m² per gram). It can remove 99.999% of gaseous substances — such as hydrocarbons, odours and vapours — by adsorbing them.

The remaining oil content is reduced to 0.003 mg/m³.

Activated carbon filters must always be preceded by an ultra-fine filter.

Note: Only oil-free condensate may be discharged into the sewer system. An oil-water separator may be required for your installation.