There is no sealing between the elements correct? Meaning some percentage of the oil randomly flows through each element?
Correct, there’s no sealing between the elements.
Someone from a Russian oil club forum wrote this (translated):
40% of the surface - 10 microns, 60% of the surface - 20 μR. The flow is one. It is easier for the oil to pass through the 20 μcr paper, we find that approximately 80% of the oil is filtered at once for 20 μm, and only the remaining 20% of the oil passes through 10 μm.
It turns out that the filter takes in only a small part of the impurities of the 10-20 micron fraction and completely more than 20 microns.