Hydraulic filters can be classified according to their filtration functions, structural features and application scenarios:

Classified by filtration function:
Air filter: It is used to filter impurities in the air entering the hydraulic system or engine.
Oil filter: It is used to filter particles in lubricating oil and protect the lubrication system of the engine.
Fuel filter: It is used to remove water and impurities from the fuel to ensure the normal operation of the fuel system.
Hydraulic oil filter: Specifically designed to filter contaminants from hydraulic oil and protect the oil pump, valves and actuators of the hydraulic system.
2. Classification by structural features:
Coarse filter: It has a relatively low filtration accuracy and is usually used for primary filtration to remove larger particles.
Fine filter: It has a relatively high filtration accuracy and is usually used for secondary or tertiary filtration to ensure the high cleanliness of the oil.
Dual filter: Composed of two filter elements, it can be used alternately. When one filter element is cleaned or replaced, the other can still work normally, improving the continuity of the system.
3. Classified by application scenarios:
Industrial machinery: such as hydraulic presses, injection molding machines, CNC machine tools, etc.
Construction machinery: such as excavators, bulldozers, cranes, etc.
Shipbuilding: Hydraulic steering gears, hydraulic pumps and other equipment for ships.
The power industry: such as generator sets, hydraulic systems of substations, etc.
Aerospace: Hydraulic control systems for aircraft and rockets.