HEAVY DUTY AIR FILTER
In traditional air filters for trucks and heavy duty machines the rigidity and resistance to mechanical damage was important. This is the reason of the massiveness of these filters. Filters have solid metal bottoms, strenghtening cores and outer casings made of net or perforated metal sheet. Cartridge sealing is provided by the rubber washers glued to the bottom. The filter medium placed inside such a solid construction is perfectly protected from deformation and mechanical damage. Such solution provides failure free exploitation. Nevertheless in the times of natural environment protection awareness, new cars are rarely equipped with these filters since their disposal is troublesome.
Modern air filters for trucks have optimized construction, which takes into account the requirements of the environmental protection standards. The load analysis of its particular elements and the selection of new materials has made the filters appearance and technological approach totally different. Polyurethane seals have replaced the metal end caps. Rubber washers are no longer applied since seals are placed in the casing. Instead of cores and casings made of perforated metal sheets, plastic reinforcement is widely used. The priority, in designing filters for trucks, is eliminating metal parts and replacing them with plastic elements, which make filter utilisation process easier.
Air filter casings in trucks are usually placed outside the engine compartments due to its large volume. Sometimes there are two filtering cartridges. In this case the inner cartridge works as a safety device stopping contaminants from flowing into the engine during cartridge replacement or protecting from mechanical damage of main cartridge medium surface during exploitation. Due to the large size of air filter casings for trucks, they are made of steel (traditional constructions) or reinforced plastic. Placing the air inlet tangent to the outer diameter makes the casing become the filter itself using the centrifugal force resulting from the air rotational motion around the filtering cartridge.