In fact, it has been estimated that 75% of hydrodynamic failures can be attributed to pollution problems. There are many reasons for liquid pollution. The use and wear of components, the pollution caused by poor pipes and new liquid (or new parts) are just some of the possibilities, which is why filters are not used, No hydrodynamic system can be complete, and hydraulic filter can prevent hydraulic oil from being polluted.
The level of filter is the standard to measure its effectiveness. One of them, ISO 4406, is the standard measurement of pollutant level in a given filtration system. The ISO 4406 code is composed of 2-3 numbers, each of which represents the logarithmic measurement of the quantity of pollutants existing in 1 ml of liquid with 3 set size ranges.
For example, a new oil sample may be 18 / 15, which is equivalent to 1300-2500 4-micron particles, 160-320 particles larger than 14 micron. Therefore, a filter with a lower ISO cleanliness level will remove pollutants more thoroughly and help prolong the life of hydraulic system components by 2-3 times.
Another indicator to measure the efficiency of the filter is the β ratio of the filter, that is, the number of pollutant particles in the upstream of the filter divided by the number in the downstream. The β ratio can be subtracted by 1, divided by β ratio, and then multiplied by 100 to get the efficiency percentage of the filter under the given pollutant size. When selecting the hydraulic filter, a larger β ratio is required.