3.4 Filtration and Conditioning

Describe the purpose of fluid in a fluid power system.


Define contaminant. Identify sources of contaminants and give examples.


Describe how oil can become a contaminant.


Describe the negative effects of contaminants in a fluid power system.


Describe the unit commonly used to measure contaminants.


Describe methods of reducing contaminant entry into a system.


Define a filter and describe a filter’s construction.


Define and differentiate between the terms nominal and absolute rating for a filter.


Define a strainer and differentiate between strainers and filters. Describe common strainer locations. Describe mesh count.


Describe a clogged filter bypass and indicator


Define beta ratio.


Calculate the beta ratio for a filter that has 1000 particles greater than 10µm upstream and 10 particles greater than 10µm downstream.


List different filter locations. Discuss the pressure requirements and describe their operation.


Describe why filters are ordinarily unidirectional. Draw an arrangement of check valves that ensures unidirectional flow through a filter given a bidirectional flow path.


Describe the additional function of a kidney loop/offline filter with respect to viscosity.


List the 3 particle sizes of concern for the ISO Standard 4406:1999.


Determine the particle count for an oil with an 18/16/13 cleanliness rating


Discuss why cleanliness standards must be considered for different applications.
Describe conditioning and differentiate between it and filtration.


Describe tube in shell and baffle heat exchangers employing liquid heat transfer fluids and comment on the purpose of counter flow.
Comment on the purpose of a reservoir and how it is used to passively condition fluid.

Range Code Particles per mL
from up to
24 80000 160000
23 40000 80000
22 20000 40000
21 10000 20000
20 5000 10000
19 2500 5000
18 1300 2500
17 640 1300
16 320 640
15 160 320
14 80 160
13 40 80
12 20 40
11 10 20
10 5 10
9 2.5 5
8 1.3 2.5
7 0.64 1.3
6 0.32 0.64



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Hydraulics and Electrical Control of Hydraulic Systems Copyright © 2016 by James Pytel is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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