My answer to Which fluid we use in shock absorber?
Answer by Arûn Râinâ:
A shock absorber (in reality, a shock "damper") is a mechanical ordevice designed to absorb and impulses. It does this by converting the of the shock into another form of energy (typically ) which is then dissipated. A shock absorber is a type of .
there have been many liquids tested for usein hydraulic systems. Currently, liquids being usedinclude mineral oil, water, phosphate ester,water-based ethylene glycol compounds, and silicone fluids. The three most common types of hydraulic liquids are petroleum-based, syntheticfire-resistant, and water-based fire-resistant.
PETROLEUM-BASED FLUIDS: The most common hydraulic fluids used inshipboard systems are the petroleum-based oils.These fluids contain additives to protect the fluidfrom oxidation (antioxidant), to protect systemmetals from corrosion (anticorrosion), to reducetendency of the fluid to foam (foam suppressant),and to improve viscosity.
SYNTHETIC FIRE-RESISTANT FLUIDS:Petroleum-based oils contain most of thedesired properties of a hydraulic liquid. However,they are flammable under normal conditions andcan become explosive when subjected to highpressures and a source of flame or high tempera-tures. Nonflammable synthetic liquids have been developed for use in hydraulic systems where fire hazards exist.
Phosphate Ester Fire-Resistant Fluid: Phosphate ester fire-resistant fluid for shipboard use is covered by specification MIL- H-19457. There are certain trade names closely associated with these fluids. However, the only acceptable fluids conforming to MIL-H-19457 are the ones listed on the current Qualified Products List (QPL) 19457. These fluids will be delivered in containers marked MIL-H-19457C or a later specification revision. Phosphate ester in containers marked by a brand name without a specification identification must not be used in shipboard systems, as they may contain toxic chemical
PHOSPHATE ESTER FLUID SAFETY.—
As a maintenance person, operator, supervisor, or crew member of a ship, squadron, or naval shore installation, you must understand the hazards associated with hydraulic fluids to which you may be exposed.