The accuracy of the hydraulic oil filter product certification or the mark on the label is the nominal accuracy, not the absolute filtration accuracy. Only the experimentally tested β value can indicate the filtration capacity of the filter element. To test the performance of the imported replacement filter element, it can be drawn from the following indicators:

1. Filtration accuracy:

Determine the cleanliness level of the stain according to the needs of the hydraulic system, and select the filtration accuracy of the oil filter according to the cleanliness level according to the attached table.

The nominal filter cleanliness of hydraulic oil filters commonly used in construction machinery is 10 μm

  Hydraulic oil cleanliness (ISO4406) Nominal filtration accuracy of the filter element μm Application range

13/10 3 Hydraulic servo valve

16/13 5 Hydraulic proportional valve

18/15 10 General hydraulic components (>10Mpa)

19/16 20 General hydraulic components (<10Mpa)

  Under the specified experimental conditions, the diameter of the larger hard spherical particles that the filter can pass through is used as its absolute filtration accuracy, which directly reflects the initial filtration capacity of the newly installed filter element.

  The β value measured according to ISO4527-1981E (multi-pass experiment) is the main standard for evaluating hydraulic oil filter elements, that is, the oil mixed with standard experimental powder is circulated through the oil filter many times, and the oil inlet and outlet on both sides The ratio of the number of particles.

2. Flow characteristics:

The flow rate and pressure drop of the filter element through the oil are important parameters of the flow characteristics. The flow characteristic experiment is carried out according to the ISO3968-91 standard to draw the flow-pressure drop characteristic curve. Under the rated oil supply pressure, the total pressure drop (filter housing The sum of the pressure drop and the filter element) should generally be below 0.2Mpa.

3. Filter strength:

The rupture-shock resistance test shall be carried out in accordance with the ISO2941-83 standard, and the pressure difference dropped sharply when the filter element is damaged shall be greater than the specified value.

4. Flow fatigue characteristics:

The fatigue test of 100,000 cycles should be carried out in accordance with the ISO3724-90 standard.

5. Experiments on adaptability to hydraulic oil:

The pressure flow bearing test should be carried out in accordance with the ISO2943-83 standard.