The braking system of industrial vehicles uses pressurized air so that the braking force transmitted by the driver is sufficient to stop the vehicle.  Air generally contains humidity which, as the temperature drops, condenses and deposits in the form of water.  This water may cause corrosion inside the braking circuit and freeze during the winter and make it difficult to brake.  To avoid condensation the air humidity must be kept at a very low level this is achieved by using a drying filter which is a porous substance that has the capacity to absorb the humidity of the air that passes through it. The humidity retained by the filter is subsequently discharged to the exterior of the braking system through a suitable air circulation.  Drying filters consequently increase the reliability and the durability of the braking system.