How to measure the viscosity density and stability of air compressor lubricating oil?
1. How to determine the viscosity and density of lubricating oil?
As the lubricant needs convection heat dissipation, the smaller the viscosity, the better. The smaller the density of the lubricating oil is, the better, because the smaller the density of the oil is, the easier the impurities and water in the oil will precipitate.
2. How to determine the freezing point of lubricating oil?
The freezing point is the temperature when the lubricating oil solidifies. The lower the freezing point is, the better. Common DB-10 lubricating oil solidifies at - 10C, db-25 lubricating oil solidifies at - 25 "C, and db-45 lubricating oil solidifies at - 45C.
3. How to determine the flash point of lubricating oil?
Flash point is also called flash point. Flash point indicates the temperature of flash fire with a little lubricating oil. It is specified that the flash point of DB-10 and db-25 lubricating oil shall not be less than 140 "C; the flash point of db-45 lubricating oil shall not be less than 135C. The lower the flash point, the greater the volatility, the worse.
4. What are the requirements for impurity content of lubricating oil?
Ash, acid, alkali, sulfur and other impurities have corrosive effect on the coil, insulator, wire and oil tank of air compressor equipment, so the lower the content, the better.
Among them, the ash content shall not exceed 1 / 10000; the impurities such as water, free carbon, active sulfur, acid-base and mechanical mixture dissolved in water shall not exist at all.
5. How is the acid value and pH value of lubricating oil specified?
The acid value represents the degree of oxidation of the oil. The mg of KOH needed to neutralize all the free acids in 1g lubricating oil is used to represent [Mg? (KOH) / g (oil)]. The lower the acid value, the better.
Acid value of specified lubricating oil is less than 0.03mg? (KOH) / g (oil). The pH value is water-soluble acid, and the pH value of lubricating oil is required to be more than 5.4.
6. How is the stability of lubricating oil regulated?
Stability is also called stability. Oil filled air compressor equipment and air long-term contact and heating, will be oxidized into acid, resin, sediment, etc., known as "aging phenomenon.".
Stability is the ability to resist "aging" of lubricating oil and maintain its original properties.
The higher the stability, the better. Stability is usually expressed by acid value and sediment content of oil after artificial oxidation. The lower these two indexes are, the higher the stability of oil is.
The acid value of lubricating oil after oxidation is less than 0.2mg (KOH) / 8 (oil), and the content of precipitate after oxidation is less than 0.05%.