A hydraulic system convey power through hydraulic fluid. Though , power transfer is the primary function of a hydraulic fluid, but there are some other important functions of hydraulic fluid such-
- As protection of the hydraulic machine components.
- Acts as medium of heat transfer
- Acts as lubricant.
Types of fluid: A correct type of hydraulic fluid is very critical for a hydraulic system. A correct hydraulic system ensure appropriate system operation and helps to avoid damage to non-metallic components of the hydraulic system. However, manufacturer’s recommendation is always followed to use hydraulic liquid to a system. There are three types of hydraulic liquids currently being used in civil aircraft:
- Vegetable base
- Mineral base
- Phosphate ester base
Intermixing of liquid: Intermixing of hydraulic liquid is strictly prohibited. In any case, if an aircraft hydraulic system be serviced with wrong type liquid we must have to drain and flush the system immediately with recommended one. Hydraulic seals should be maintained according to the manufacturer’s specifications.
Contamination of liquid: There is always a chance of contamination of Hydraulic liquid during its operation and service. The nature of trouble created by contaminated liquid depends on the types of contaminants:
There are two types of contaminants:
- Abrasives: including such particles as core sand, weld spatter, machining chips, and rust.
- Non-abrasive: including those resulting from liquid oxidation, and soft particles worn or shredded from seals and other organic components