Gas Filters WITT gas filters allow the reliable filtration of the finest dirt particles in gases. Depending on the respective version, the gas filters can filter out particles from 3 to 40 micron and extend the service life of downstream equipment. The WITT gas filters provide high flow rates and multiple connections. WITT gas filters can be used for many technical gases. The gas filters – with or without condensation outlet – are designed for installation in pipelines or at outlet points. Gas filters can be changed while installed.