What Causes Cavitation?
(1) Analysis of Cavitation
Cavitation is the formation of vapor bubbles of a liquid in a region where the pressure of the liquid falls below its vapor pressure. When the cavitation bubbles collapse, they force energetic liquid into very small volumes, thus creating spots of high temperature and emitting shock waves. The highly localized collapses can produce great wear on components of hydraulic cylinders.
(2) Cavitation Caused by Unqualified Hydraulic Oil
High quality hydraulic oil can effectively prevent cavitation. Bubbles can be easily formed in oil with poor antifoaming ability, thereby resulting in cavitation. In addition, if the frequency of oil pressure change is too high, air bubble formation and collapse can also be largely accelerated. Moreover, overheated oil will also increase the possibility of cavitation.
(3) Cavitation Due to Improper Manufacture and Maintenance
In the assembly or maintenance, air in hydraulic system is not discharged, which could cause cavitation under high temperature, high pressure conditions.
(4) Cavitation Resulting from Poor Quality Coolant
The coolant which contains corrosive medium like acid radical cation and oxidant is liable to chemical, electrochemical corrosion, thereby accelerating the speed of cavitation.