Grease knowledge quick question quick answer! Want a challenge?

January 13, 2024

Grease knowledge quick question quick answer! Want a challenge?

01 What are the uses of various additives in lubricating oil?

1) The effect of the detergent dispersant has four kinds of solubilization, dispersion, acid neutralization and adsorption.

2) The role of antioxidant and antioxidant anti-corrosion additives is to inhibit the oxidation process of oil products, passivate the catalytic effect of metal on oxidation, and achieve the purpose of extending the use of oil products and protecting the machine.

3) The function of the anticoagulant is to reduce the freezing point of the oil, so that the oil can maintain good fluidity at low temperature, and improve the low temperature starting performance of the engine.

4) The Viscosity Index Improver can increase the viscosity of the oil, especially to meet the low temperature performance requirements of the oil.

5) Oiliness agent and extreme pressure anti-wear agent can chemically react with the metal surface to form a chemical reaction film to prevent wear, abrasion and fusion welding on the metal surface.

6) The role of anti-rust agent includes the formation of an adsorbent protective layer on the metal surface, preventing the corrosive medium from contacting the metal, and playing an anti-rust role.

7) The main function of anti-foam agent is to inhibit the generation of foam, so as not to form a stable foam, it can be adsorbed on the bubble film, forming an unstable film, so as to achieve the purpose of destroying the foam.

8) The anti-emulsifier can change the tension of the oil/water interface, so that the oil and water are separated, and the purpose of improving the anti-emulsification property of the oil is achieved.

02 What is Pour Point?

A: When the oil is cooled under the conditions specified in the standard, the lowest temperature at which it can continue to flow is called the pour point. When choosing lubricating oil, it is usually necessary to consider the pour point of lubricating oil, and the pour point of lubricating oil should be 5 to 10 degrees lower than the lowest temperature of the environment.

03 What is Flash Point?

A: Under the specified conditions, heating lubricating oil, when the oil temperature reaches a certain temperature, the mixture of lubricating oil vapor and surrounding air, once in contact with the flame, that is, flash fire phenomenon, the lowest flash temperature, called the flash point of lubricating oil. When selecting lubricating oil, the flash point of lubricating oil should be considered according to the use temperature, and the flash point should be 20 to 30 degrees higher than the use temperature to ensure the use of safety and reduce volatilization loss.

04 What is the acid number?

A: The acid value of the lubricating oil is a quality indicator indicating the total amount of organic acids in the lubricating oil (in most cases, the oil does not contain inorganic acids). The number of milligrams of potassium hydroxide required to neutralize 1g of petroleum product is called the acid number. The acid value of lubricating oil has a great influence on the use of lubricating oil. The large acid value of lubricating oil indicates that the organic acid content of lubricating oil is high, which may cause corrosion to mechanical parts, especially when there is water, this corrosion effect may be more obvious. In addition, the lubricating oil is oxidized and deteriorated during storage and use, and the acid value also gradually increases. The size of the acid value change is commonly used to measure the oxidation stability of the lubricating oil, or as an oil change indicator.

05 Can lubricating oil be stored in high temperature environment?

A: No, because the oil can play a role in lubricating protection, viscosity is a very important factor, the viscosity of the oil generally changes with the temperature. When the temperature is high, the oil will become thinner, on the contrary, when the temperature is low, the oil will become thicker, some of the oil this change is very large, and some are very small, high-quality oil looks very thick at room temperature, but it becomes very thin at high temperature, and it cannot be lubrically protected.

06 What are the components of grease?

A: Grease is composed of three parts: Base Oil, thickener and additive, of which the base oil accounts for about 70%-90%, the thickener accounts for 10%-20%, and the additive content is less than 5%;

1, base oil: it is an important part of grease, grease lubrication properties depend on the lubrication of the base oil, so the correct choice of base oil is very important.

2, thickener: is an important part of the grease, it forms a skeleton in the grease, the base oil adsorbed and fixed on the skeleton to form a colloid. The nature and content of the thickener determine the viscosity of the grease and the performance of water resistance and heat resistance.

3, additives: its role is to improve some performance of the grease. If the Ep Additive is added, the EP performance of the grease can be improved; The anti-rust properties of grease can be improved by adding anti-rust additives.

07 What is a drop point?

A: The drop point is that the grease is heated under specified conditions. The grease softens with increasing temperature, and the temperature at which the first drop drops from the grease cup is called the drop point. Generally speaking, the maximum temperature limit of the use of grease should be lower than its drop point of 30℃-50℃. However, for the use of low speed, the maximum operating temperature limit of the grease can be lower than the drop point of 15°C-30 °C. It should be noted that the drop point is not the only parameter to determine the maximum operating temperature limit of the grease; To determine the maximum operating temperature limit of a grease, in addition to the drop point, the consistency of the grease at high temperature, the oxidation resistance of the base oil and the thickener, the colloidal stability at high temperature and other parameters should be considered.

08 What is needle penetration?

A: Also known as cone penetration, is a measure of the consistency of grease (that is, the degree of softness and hardness) indicators; At the specified temperature and load, the standard cone of the coneometer sinks vertically into the depth of the grease sample within 5s. Other factors should be considered when choosing a grease, not only considering the cone penetration index; In particular, a misconception should be corrected here that the less cone-in (that is, the thicker) the fat, the better the resistance to high temperatures. Nor can the coning degree be understood as a parameter equivalent to the viscosity of the lubricating oil, for example, the heavy and low speed machinery needs to use a viscous lubricating oil, rather than the use of thicker grease, on the contrary, the need to use a softer grease (but the viscosity of the base oil of the grease should be larger).

09 What are the identification methods of lubricating oil quality?

1. Appearance and smell

(1) The oil is clean and clear, and still maintains the golden yellow or dark brown of the new oil, indicating that the pollution is very light.

(2) Foggy or cloudy, indicating that the oil is polluted by water or antifreeze. Less water content in mist, more water content in turbidity or emulsion.

(3) the color turns gray and may be contaminated by leaded gasoline; Incomplete combustion of fuel will make the lubricating oil turn dark black very quickly.

(4) After the lubricating oil has been standing for a period of time, it is normal if the oil color remains unchanged.

(5) Abnormal odor is one of the characteristics of lubricating oil pollution. High temperature oxidation of lubricating oil with burning irritating odor, heavily diluted lubricating oil with gasoline or light diesel odor.

2. Popping sound

Make a small dish of aluminum foil or other metal sheet and heat it for 1-2 minutes before adding 3 to 4 drops of shaken lubricating oil. If the oil foam splashing, indicating that the oil contains more water; If there is an immediate explosion, it means that there is a trace amount of water; The intensity and duration of the sound are related to the water content.

3. Oil flow observation

When the lubricating oil flows without pollution, the oil flow should be slender, uniform and continuous; If the oil flow is fast and slow, and sometimes there is a large liquid flowing down, it indicates that the oil has deteriorated.

4. Traces of oil drops

Take a clean white test paper, drop a few drops of oil on the paper, such as oil penetration, if there is black powder on the surface, touch with the hand has a sense of Yin, it means that there are more impurities in the oil; The uncontaminated oil is powderless and has yellow traces.

10 How to identify whether the lubricating oil has deteriorated?

1, the lubricating oil is deep black (refers to the lubricating oil without clean dispersion additives).

2, more foam and emulsification has occurred.

3. Twist with fingers, sticky, astringent or smelly.

4, drop on the white paper is dark brown, no yellow infiltration slip area or a lot of black spots.

11 What are the basic requirements for indoor storage of lubricating oil?

Indoor storage: It is the most ideal storage method, and the oil drums are centrally stored in the designated place in the plant, which can save a lot of handling time and is very convenient. Oil drums should never be stored near steam lines or heaters. If the plant cannot accommodate the pending lubricating oil; The best way is to use a nearby warehouse for temporary storage, but shelves should be installed, and a lifting platform should be set up nearby to smoothly place the oil drums. Arrangement of various types of lubricating oil application systems for easy access. The principle of "first in first use" can reduce the chance of oil quality deterioration due to excessive storage.

12 What are the basic requirements for indoor storage of lubricating oil?

A: Outdoor storage: It is a bad practice to store lubricating oil outdoors. However, if it must be stored outdoors for space reasons, some preventive measures should be taken to minimize the adverse consequences: temporary tents or waterproof canvas can protect the oil drum from rain erosion, and must be stored on the shelf more than 10 centimeters from the ground to prevent moisture damage; The oil drums should be placed horizontally so that the two drums on the lid of the drums are plugged in the same horizontal line; When the barrel must be placed with the barrel stopper facing upward, the barrel should be tilted by a wooden strip at the bottom of one side of the barrel, and the two barrels should be connected in a straight line parallel to the wooden strip, so that water can be kept away from the opening of the barrel stopper.

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