I use a gas water pump with a spin on filter to filter my wate motor/hydraulic/misc. oil. I pour or pump my oil into a holding barrel and let it sit for a while-the longer the better. Then I pump into a big 280gal holding tank and let it sit again. From there I pump into the tank. I use a single 10 micron filter on the output side of my suction pump. I keep an eye on the the oil coming out of the end of the hose to known when a filter is clogging. You won't get a complete clog unless you are getting water which thickens and clogs filters. I can fill up faster or at least as fast as a normal gas station. SO far I think I did 1500miles in the deuce, 1500 in the 5 ton, maybe 20/30 gallons in the 10 ton, and 1000miles in my F350.
I also NEVER pump from the bottom and always try to stay as far up in the oil with the end of my pick-up as possible.
When you think about it, oil filters are usually 20-30 micron filters. If 20-30 microns isn't going to harm machine bearing surfaces then I think our injection pump will be well in the clear filtering with 10 microns.