- Atmosphere is an important factor that causes hydraulic system failure. At 1 standard atmospheric pressure, about 9% of the air can be dissolved in the oil. At high pressure, air and others are more soluble in the oil, and when the pressure is reduced, they escape. Therefore, the hydraulic system should be vented before operation to avoid serious failure.
The common method is to repeatedly jog the hydraulic system switch several times to release the air in the pump or valve before starting for the first time or after a long shutdown.
1、Cavitation problems of seals.
- When the gas dissolved in the liquid is released to form bubbles and exist in the liquid, this phenomenon is called cavitation. Cavitation will not only cause flow pulsation, but also burst under high pressure in severe cases, which is cavitation. Cavitation creates noise and shock vibrations that can scratch not only the seals, but also the solid surfaces in contact.
- Once the surface of the seal is damaged by pits and air hole pits, the hydraulic oil flows through the longitudinal scars at a very high speed and with great acceleration to intensify the wear, and the broken particles on the metal surface are scratched again with the flow of the liquid. seals and sealing surfaces, thereby accelerating the process of seal failure.
- Therefore, it is necessary to prevent gas pollution and cavitation in the compression body. An exhaust device should be installed in the liquid system. In view of the characteristics that cavitation generally occurs in the narrow channel and the surge of liquid flow rate, the design should try to avoid sudden change of pipe diameter and control The pressure ratio of the abrupt change.