Liquid filters are an indispensable device on the conveyor pipe, usually mounted on the pressure reducing valve, pressure relief valve, water valve inlet port or other equipment, used to eliminate impurities in the media in order to protect the valves and the normal use of the equipment. When the fluid must enter the location specification after the filter cartridge, the impurities are blocked, and clean filtrate from filter egress, when cleaning is needed, just take out the removable filter cartridges, reload after the treatment, therefore, maintenance is very convenient.