The installation locations of oil filters in hydraulic systems are typically as follows:
⑴ Installed at the pump's suction port: Surface-mounted oil filters are generally installed on the pump's suction line to filter out larger particles of impurities, protecting the hydraulic pump. Furthermore, the filter's filtration capacity should be at least twice the pump's flow rate, and the pressure drop should be less than 0.02 MPa.
⑵ Installed on the pump's outlet line: The purpose of installing the oil filter here is to remove contaminants that may enter valves and other components. Its filtration accuracy should be 10–15 μm, and it should be able to withstand the working pressure and impact pressure on the oil line, with a pressure drop of less than 0.35 MPa. A safety valve should also be installed to prevent filter clogging.
⑶ Installed on the system's return line: This installation provides indirect filtration. A back pressure valve is generally installed in parallel with the filter; when the filter becomes clogged to a certain pressure value, the back pressure valve opens.
⑷ Installed on a branch line of the system.
(5) Separate Filtration System: Large hydraulic systems can have a dedicated hydraulic pump and oil filter forming an independent filtration circuit.
In addition to the oil filter required for the entire system, hydraulic systems often have a dedicated fine oil filter installed before some important components (such as servo valves, precision throttle valves, etc.) to ensure their proper functioning.
