Hydraulic System Components and Design Spokane Community College

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

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.

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.

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

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

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

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

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

Basic Hydraulic Systems Open Hydraulic System. Closed Hydraulic System.

Open Hydraulic System

Closed Hydraulic System

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