1. Filters

2. List 4 types of contaminants
Water--acid
Metal Burrs and chips
Dust, sand, pieces of seals and paint rust
lint, fibers

3. Explain the concept of a micron
Measure of the opening hole size of a filter. The size of particle that can pass through the filter
Micron 3.95 x 10 to the -5 or inches or millionth of an inch
10 mu = 1/10 size of a grain of table salt
Particles of 40 to 50 microns are visible

4. Explain the difference in a filter and a strainer
A filter can catch smaller particles than a strainer

5. Three Types of Filter Rating
Mean - the average size of pore opening in the filter. Absolute - The size of the largest opening in the filter, removes 100% . Nominal - that is given to the by the manufacturer. Nominal rating - Ex. 10 microns traps most particles (98%) 10 or larger (largest 25um).

6. Surface and Depth Filters.
A. Surface
B. Depth
ab absorbent -- Mechanically remove dirt.
ad adsorbent -- Mechanically and Chemically remove dirt. charcoal, chem treated paper, fuller earth) Works to remove oil oxidation, even additives

7. Describe the two most common types of filtration systems
Full-flow-- filters entire supply of oil as it circulates in the hydraulic system
Bypass-- small portion of oil is diverted through the filter

8. Difference in surface and depth filters
Surface-- have a single surface that catches and removes dirt particles
Depth-- thicker filtering area

9. Describe features of various types of filters
Has indicator to tell when to change
Sensors to tell if stopped up
Disposable vs washable

10. Explain the appropriate procedure for maintaining the filter
Check filter according to recommendations in the manual
replace filter according to recommendations in the manual
following manual’s directions
check to make sure you are using or installing the right filter