Filter paper requirements
　　Oil filters have higher requirements on filter paper than air filters, mainly because the temperature change of oil varies from 0 to 300 degrees, under the drastic temperature change, the concentration of oil also changes correspondingly, which will affect the filtration flow of oil. The filter paper of high quality oil filter can filter impurities and ensure sufficient flow rate under the drastic temperature change.
　　role
　　Oil filter in the lubrication system in order to make the lubrication system oil flow unimpeded, to avoid impurities scratch, brushed parts surface, oil in the friction surface, must be strictly filtered. In order to achieve a satisfactory filtering effect without increasing the oil resistance, the coarse filter is usually connected in series with the main oil channel, and the fine filter is connected in parallel with the main oil channel.