Cartridge filters consist of multiple cylindrical tubes mounted on holders in a pressure tank. The holders seal the ends of the tube so the water must pass through the walls of the cartridges. Depending on the requirements of the process and the required filtration capability, a cartridge filter may be made with any numbers of materials. They are rated as to the medium particle size they will pass.
If a particle is too big to pass through the filter material, it becomes entrapped in the wall of the cartridge. This will lead to a gradual plugging of the cartridge. If the pressure differential across the filter is too great, the filter must be replaced. Due to the design, backwashing these filters is not typically done.
A common every day example of a cartridge filter would be the type of filter that is found in a backyard pool.