Types of fluid contamination in hydraulic systems

In the hydraulic system, it is very important to ensure that the hydraulic oil is not contaminated. The degree of pollution of hydraulic oil directly affects the normal operation and reliability of the hydraulic system. According to the statistics of the editor, about 70% of hydraulic system failures are caused by the contamination of hydraulic oil. This article briefly summarizes the five types of hydraulic oil pollution.

1. Moisture: Moisture mixed with hydraulic oil will cause cavitation in the hydraulic system at high temperature and high pressure; after cooling down, water condenses into water droplets, corrodes metals, and accelerates oil oxidation; when the temperature is lower than 0°C, it may even freeze and block oil circuit.

2. Air: Air mixed into the hydraulic oil can cause noise in the hydraulic system, causing cavitation, crawling and vibration; at the same time, the air can also accelerate the oxidation of the oil, making the performance of the hydraulic oil worse.

3. Other oil products: When the hydraulic oil is mixed with other oil products, the chemical composition of the hydraulic oil is changed, and the viscosity of the hydraulic oil may be changed to affect the efficiency of the system; if the hydraulic oil is mixed with flame retardant fluid, the hydraulic oil The compatibility with the sealing material is destroyed, leading to serious consequences such as sealing failure.

4. Self-oxidation product: The viscous substance produced by the gradual oxidation of hydraulic oil due to high temperature and high pressure will block the damping hole or throttle of the component and affect the normal operation of the system.

5. Mechanical impurity particles: This is the most harmful pollution. Generally, the pollution of hydraulic oil mainly refers to the pollution of particle impurities.