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Introduction to hydraulic filters

According to their filtration precision (the particle size of impurities filtered out), hydraulic filters are divided into four types: coarse filter, ordinary filter, precision filter and special fine filter. They can respectively filter out particles larger than 100μm, 10-100μm, 5 ~10μm and 1~5μm size impurities.

hydraulic filters

Things to note when choosing hydraulic filters

When choosing hydraulic filters, consider the following points:

(1) Filtration accuracy should meet predetermined requirements.

(2) Sufficient flow capacity can be maintained for a long time.

(3) The filter core has sufficient strength and will not be damaged by hydraulic pressure.

(4) The filter core has good corrosion resistance and can work permanently at the specified temperature.

(5) The filter element is easy to clean or replace.

Where to install hydraulic filters

The installation locations of hydraulic filters in hydraulic systems are usually as follows:

(1) It should be installed at the suction port of the pump:

Surface hydraulic filters are generally installed on the suction path of the pump to filter out larger impurity particles to protect the hydraulic pump. In addition, the filtration capacity of
hydraulic filter elements should be more than twice the pump flow rate, and the pressure loss should be less than 0.02MPa.

(2)Installed on the outlet oil line of the pump:

The purpose of installing hydraulic filters here is to filter out contaminants that may intrude into valves and other components. Its filtration accuracy should be 10~15μm, and it should be able to withstand the working pressure and impact pressure on the oil line, and the pressure drop should be less than 0.35MPa. At the same time, a safety valve should be installed to prevent the
hydraulic filter elements from clogging.

(3)Installed on the oil return line of the system:

This installation plays an indirect filtering role. Generally, a back pressure valve is installed in parallel with hydraulic filters. When the filter is clogged and reaches a certain pressure value, the back pressure valve opens.

(4)Installed on the system branch oil line:

installed Liming oil suction filter element is installed on the branch oil line of the system.

(5)Individual filtration system:

Large hydraulic systems can be equipped with a hydraulic pump and hydraulic filters to form an independent filter circuit.


In the hydraulic system, in addition to the hydraulic filter elements required by the entire system, a dedicated fine oil filter is often installed separately in front of some important components (such as servo valves, precision throttle valves, etc.) to ensure their normal operation.

Reference blog :Hydraulic Filter Elements.Btlas filter manufacturer for Donaldson filter.The Importance of Hydraulic Filter: Exploring the Donaldson Difference.How to choose filter in hydraulic system?Oil filter elements : improve hydraulic system performance!Donaldson Hydraulic Filter VS Btlas Hydraulic Filter.What is the difference between hydraulic oil filters and oil filter elements?

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