Fuel filters

[Chamberpains]

The purpose of the 140 micron filter is to catch all the big chunks first but still allow fuel to keep traveling then the 15 micron filter catches all the small particles. It keeps one filter from getting jammed up with small and large particles all at once. So you might find you're 10 micron filter getting plugged up really fast because it's catching everything coming out of the tank. And now making your 15 micron filter a redundant filter not doing anything because you're 10 micron filter caught everything.