A hydraulic filter is an important device used to filter impurities in hydraulic systems. Its core function is to remove particles, water and other contaminants from hydraulic oil through the filter element, thereby ensuring the normal operation of the hydraulic system and extending the service life of the equipment.

The working principle of the hydraulic filter
Filtration process
After the hydraulic oil enters the filter from the hydraulic system, it passes through the micro-porous structure of the filter element (composed of filter screens or filter paper) to retain impurities (such as metal particles, dust, moisture, etc.).
The clean oil that has not been contaminated enters the hydraulic system through the filter element and continues to circulate.

Automatic cleaning process
When impurities on the surface of the filter element gradually accumulate, causing the pressure difference between the inlet and outlet to reach the set value, the control system will activate the backwashing or cleaning mechanism.
The impurities adhering to the filter element are removed by the motor driving the brush to rotate or by using the reverse water flow, and then discharged from the system through the drain port.
After the cleaning process is completed, the system returns to the filtration state. The entire process can be fully automated without the need for manual intervention.

Overflow protection mechanism
Some hydraulic filters are also equipped with relief valves. When the filter element is completely clogged, the oil can bypass the filter element through the relief valve to prevent equipment damage caused by excessive system pressure.
The filtration accuracy of hydraulic filters is usually measured in micrometers (μm), and common grades include 5μ, 10μ, 20μ, etc. High-precision filters can remove smaller particles and are suitable for systems with extremely high cleanliness requirements.