Page 41 - PNEUMATIC AND HYDRAULIC

As a medium by which is its to transfer the power, an ideal fluid is required. An ideal

fluid should have these characteristics, such as:

i. Fluid thermal stability

ii. Fluid hydrolytic stability
iii. Low chemical corrosiveness effect

iv. High anti-wear characteristics
v. Low tendency to cavitate or bubble

vi. Long life

vii. Total water rejection
viii. Constant viscosity, regardless of temperature, and

ix. Low price cost.

There is a several factors can influence hydraulic fluid performance must be

considered, such as:

i. Viscosity - Maximum and minimum operating temperatures, along with the
system's load, determine the fluid's viscosity requirements. The fluid must

maintain a minimum viscosity at the highest operating temperature. However,
the hydraulic fluid must not be so viscous at low temperature that it cannot be

pumped.

ii. Foaming - When foam is carried by a fluid, it degrades system performance

and therefore should be eliminated. Foam usually can be prevented by

eliminating air leaks within the system.

iii. Corrosion - Two potential corrosion problems must be considered: system

rusting and acidic chemical corrosion. System rusting occurs when water

carried by the fluid attacks ferrous metal parts.

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