Precision filter is an indispensable device on the transmission medium pipeline. It is usually installed at the inlet end of pressure reducing valve, pressure relief valve, fixed water level valve or other equipment. It is used to eliminate impurities in the medium and protect the valves and equipment used normally. When the fluid enters the filter cartridge equipped with a certain size of filter screen, its impurities are blocked, and the clean filtrate is discharged from the filter outlet. When cleaning is needed, can just take out the detachable filter cartridge, process it and reinstall it. Therefore, its use and maintenance are extremely convenient. It is widely used in drinking water treatment, building circulating water treatment, industrial circulating water treatment, sewage treatment, mining industry water treatment and other fields.