1. Hydraulic System Components and Design
Spokane Community College

2. Hydraulic Fluid Characteristics
Viscosity
Viscosity is a internal resistance to flow.
The viscosity is reading in SSU (Seconds Saybolt Universal)

3. Hydraulic Fluid Characteristics
Chemical Stability
It is the ability liquid to resist oxidation and deterioration for long periods.
Flash Point
Flash point is the temperature at which a liquid gives off vapor in sufficient quantity to ignite momentarily when a flame is applied.

4. Hydraulic Fluid Characteristics
Fire Point
Fire point is the temperature at which a substance gives off vapor in sufficient quantity to ignite and continue to burn when exposed to spark or flame.

5. Characteristics of a good hydraulic fluid
A good Viscosity (no too high but no too low)
A good Chemical Stability.
High Flash Point
High Fire Point

6. Types of Hydraulic Fluids
Type of Fluid
Base
Color
Vegetable
MIL-H-7644
Castor oil and Alcohol
Dyed Blue
Mineral
MIL-H 5606
Kerosene
Dyed Red
Synthetic
SKYDROL
Non-petroleum base
Dyed light purple

7. Important Can you mix different types of Fluid?
Never Mix two different kinds of hydraulic fluid!!

8. Hydraulic Fluids and Seals Material
Type of Fluid
Seals Material
Vegetable
MIL-H-7644
Natural rubber
Mineral
MIL-H 5606
Neoprene
Synthetic
SKYDROL
Natural or Synthetic fiber

9. What to do if you used the wrong Hydraulic fluid
Type of Fluid
The system may be flushed with…….
Vegetable
MIL-H-7644
Alcohol
Mineral
MIL-H 5606
Naphtha, Varsol or Stoddard solvent
Synthetic
SKYDROL
Trichlorethylene

10. Basic Hydraulic Systems
Open Hydraulic System.
Closed Hydraulic System.

11. Open Hydraulic System

12. Closed Hydraulic System

13. END