Oil suction filter and oil return filter

In the hydraulic system, there are two seemingly inconspicuous but vital components – the oil suction filter and the oil return filter. Many people often confuse them and even mistake them for the same product. But in fact, they each have their own functions in the hydraulic system, with obvious differences and unique values.

1. Oil suction filter element

The oil suction filter element is on the oil suction filter, tightly guarding the oil suction port of the oil pump. We know that there are often a large number of large solid impurities hidden in the hydraulic oil. These impurities are like “time bombs”, which seriously threaten the safe operation of the hydraulic system and the service life of hydraulic components.

It effectively controls the pollution level of the hydraulic system by preventing the inhalation of common impurities, greatly improving the cleanliness of the system. It can prevent larger particles of impurities from rashly entering the oil pump and avoid malfunctions. At the same time, it can also avoid difficult problems such as filter valve core jamming to a certain extent.

The oil suction filter element itself also has distinct characteristics:

(1) Strong oil flow capacity:

It can ensure sufficient supply of liquid, meet the flow demand of the oil pump, effectively prevent the occurrence of suction, and keep the oil pump in good working condition.

(2) High efficiency of filtration:

It has excellent filtration effect on large particles of solid impurities, always maintains the cleanliness of the oil, and lays the foundation for the stable operation of the hydraulic system.

(3) Minimal original pressure loss:

While ensuring the filtration effect, it minimizes the impact on the system pressure as much as possible, so that the hydraulic system can operate efficiently.

(4) High-quality glass fiber filter material:

The use of glass fiber filter material not only has good filtration effect, but also has a long service life, reducing frequent (5) Coarse filter element properties: It focuses on intercepting larger particles of impurities and plays a key initial filtration role in the filtration system of the entire hydraulic system.

2. Oil return filter

The return oil filter is located in the return oil pipeline or return oil line. It filters and removes pollutants generated or invaded in the system before they return to the oil tank. This is of great significance for protecting the oil pump and various hydraulic components, especially delicate components such as gear pumps and plunger pumps.

The return oil filter also has its own unique features:

(1) Fine filtration accuracy:

Its filtration accuracy is usually between 10-30um, which can accurately capture those tiny pollutants, ensure that the oil returned to the oil tank is purer, and provide clean “blood” for the circulation of the entire hydraulic system.

(2) Specific installation position:

It is installed on the hydraulic return oil pipeline, that is, at the rear end of the oil pump outlet. When the oil completes the working cycle and is about to return to the oil tank, it performs the final “purification check”.

(3) Fine filter positioning:

With its fine filtering ability, it belongs to the category of fine filter elements and plays an irreplaceable role in ensuring the normal operation of precision components in hydraulic systems.

3. Key points for filter element selection

Suction filter elements and return filter elements are not the same product. Their unique design and performance determine that they must be carefully selected when used. In terms of filter element selection parameters, the following points need to be focused on:

(1) Filtration accuracy:

According to the specific requirements of the hydraulic system and the degree of contamination of the oil being processed, accurately select the appropriate filtration accuracy to ensure that impurities can be effectively filtered without excessively affecting the flow and pressure of the system.

(2) Material:

Different materials have different corrosion resistance, strength and filtration performance. It is necessary to select the appropriate filter element material, such as glass fiber, stainless steel, etc., in combination with the environment in which the hydraulic system is located and the characteristics of the oil.

(3) Flow rate:

Ensure that the flow rate of the filter element can meet the actual needs of the hydraulic system to avoid poor system operation or premature clogging of the filter element due to insufficient flow.

(4) Structure and external dimensions:

It must be compatible with the installation space and pipeline layout of the hydraulic system to ensure that the filter element can be installed smoothly and work stably.

Selecting the appropriate filtering equipment, the selection of the filter element is undoubtedly a crucial link. Only by deeply understanding the differences and characteristics of the oil suction filter element and the oil return filter element, and accurately selecting the filter element according to actual needs, can the hydraulic system operate efficiently, stably and safely, providing strong support for our production and life.