The filter element can purify the polluted medium and reach the clean state required by production and life, with a certain degree of cleanliness. Filter elements are widely used, ranging from industrial production such as steel smelting, power production, marine purification, etc. to drinking water treatment, domestic waste utilization, automobile fuel filtration, bicycle lubricating oil filtration, etc. Therefore, filters and filter elements are used in cleaning technology in daily life. The hydraulic system is divided into: oil suction filter, pipeline filter and oil return filter
