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Q:How is the lubricating oil composed?A:Lubricating oil is composed of base oil and additives, among which base oil accounts for more than 80%. Therefore, the quality of base oil directly affects the performance and manufacturing cost of finished lubricating oil.
Q: What kind of base oil?A: The types of base oils fall into the following 5 categories :(from low to high quality)
The first kind , traditional solvent refined mineral oil;
The second kind, hydrocracking mineral oil; Both of these are called mineral oils, and the base oil of mineral oils is the fractional distillation of useful light substances (such as aviation oil, gasoline, diesel... After that, the remaining base oil is refined (then asphalt). In essence, it uses the poor components of crude oil, in which there are thousands of different mixtures of molecules. Even with the most sophisticated refining techniques, it is impossible to remove all the undesirable substances and impurities.
The third type, highly hydrolyzed or hydroisomerized wax; This type of base oil is the same as the first two and is "the least conceptually clear product" on the market today. It is representative that Castrol not only started in 1999, but also used VHVI (very high viscosity index), a class III base oil, to replace the original PAO and not viscosity, with the "synthetic"- synthetic oil label. Now many domestic brands not only viscosity but also imitate. With the improvement of processing technology, there are now 1DW (hydrocracking - isomerization dewaxing) on VHVI, which is patented by Chevron company; MSDW (Hydrotreating -- Hydroisomerization and hydrocracking -- selective dewaxing) is a patent of ExxonMobil. XHVI (Hydroisomerization to produce ultra high viscosity index), a Shell patent, is now known as synthetic base oil. Exxonmobil semi-synthetic oil is basically the use of MSDW technology, called synthetic technology. But in fact, the lubricating oil based on this kind of base oil is still in the category of mineral oil.
The fourth group, polyalpha-olefins (PAO); Polyalpha-olefins (PAO), an ExxonMobil proprietary technology, is derived from gas or ethylene or propylene dispersed from crude oil, which is then polymerized, catalyzed and other complex chemical reactions to produce a base liquid composed of large molecules. In essence, it is used in the crude oil better ingredients, chemical reaction and through the people under the control of the desired molecular form, its molecular order, natural ability to resist external variables is very strong, so better synthetic oil physique, the thermal stability, oxidation reaction, the viscosity changes of resistance is much better than mineral oil nature.
At present, the lubricating oil products with four kinds of base oils as the main components are most commonly seen in the market. At the end of this paper, you will see the international brand lubricating oil products corresponding to these five types of base oils, hoping to help you.
The fifth category, other synthetic oils (generally referring to ester synthetic oils) are diesters, polyols, polyethers, silicone oils, phosphate esters, etc., which are synthesized through the extraction of kinetic, plant (biological) fatty acids and alcoholization. Esters are inherently oily and have natural lubrication properties (other base oils, including PAO, are made available through additives). Moreover, the original polar properties of esters can make oil film molecules stick to the metal surface, so ester lubricants are the best lubricants in terms of their properties.
Q: Why are additives added to lubricants?A: Lubricating base oil has the basic characteristics and some performance of lubricating oil, but only by improving the processing technology of lubricating oil, it cannot produce lubricating oil with all kinds of performance meeting the requirements of use. In order to make up for the defects of some properties of lubricating oil and give lubricating oil some new excellent properties, a variety of additives with different functions should be added in the lubricating oil. The amount added ranges from a few parts per million to a few tens of percent.
Q: Why does the oil go black?A: Lubricating oil in the lubrication process black is a normal phenomenon, because the oil in a long period of high temperature under natural oxidation. 2 engine fuel in the work process will inevitably produce low-temperature sludge, such as high carbon deposition and coke quality, friction also can produce metal powder, the parts in the lubricating oil detergent-dispersants these sludge, carbon, metal powder, such as washing down, and scattered into a suspension of extremely small particles in the lubricating oil, so oil will be natural black color, but does not affect the normal use of lubricating oil. If the engine cylinder head, piston ring, spark plug and the top of the piston carbon accumulation is serious, and the oil removed is more clear, it indicates that the oil cleaning is not good. If a large amount of oily sludge is found on the base of the lube oil, it indicates lube oil.
Q: What is the phenomenon, cause and treatment of pressure oil deterioration?A:The phenomenon of pressure oil metamorphism is that the pressure oil appears foamy or milky white.
The reason for the deterioration of pressure oil is that air and water enter the oil pressure system; Pressure oil shortage; Poor oil quality; The nozzle of the return tank is not under the pressure of immersion oil; Cooling water leakage into the tank, etc.
The treatment method is:
1.Select appropriate national standard pressure oil; Work under proper pressure; Check the oil pump; Special attention should be paid to check whether there is leakage inside the oil cooler; Do not open the cylinder head casually.
2.The whitened oil can be vaporized at 80C-100C temperature and tested before use.
Q:How to identify the quality of lubricating oil? (Sharing of Vehicle Mechanics)A:In the current lubricating oil market, various brands of fake oil abound, more than 50% of them are fake and shoddy, the proportion of gasoline used in cars is higher, it is difficult to buy a good oil! The fake oil of 20-80 yuan sells 100-400 yuan above, a lot of people rush into danger to make money against one's heart in order to make huge profits, seriously damage the owner's interests, cause the vehicle three days two bad, let a lot of owners want to cry without tears! Need not be afraid, have our "fire eye gold eyeball", can let you see oil product market clearly, clearly.
Look at the outer packing of oil products. The packaging of authentic goods is exquisite, with special marks on the inconspicuous places such as the bottom, inside of the lid and the handle; However, the packaging of fake products is mostly rough, and the color is generally lighter than the real products. The real products are clear where the product is printed, while the fake products may not be clear.
Two distinguish, see oil color. Genuine new oil is light yellow, crystal clear, no impurities, no suspended matter, no precipitation, uniform flow; The used oil is black and shiny, like a mirror, and as viscous as the new oil.
Three smells, no special smell, only slightly fragrant. False oil opens oil drum to can smell a petrol, diesel flavour commonly, to olfactory stimulation is big and the oil that has peculiar smell is bad or inferior oil, absolutely cannot use. The weight of real oil is generally accurate, while the weight of fake oil varies greatly from barrel to barrel.
Four frozen, if possible, put half a bottle of oil in a transparent container and seal the bottle mouth, with a number of plastic bags tied tightly, to prevent oil leakage pollution refrigerator, oil is toxic. Freeze in the freezer for a few hours, at -20 degrees temperature must still be able to flow, do not freeze, otherwise it is fake oil.
Five. For enquiries.
Six, don't trust anyone. Oil drums must be taken away to facilitate claims; Find false must call 12315 report, and tell you all the people you know. He can take fake oil pits. You're not your friend anymore.
Seven by seven, if it can't save you money and time, it must be false
Q: How to store lubricating oil inside and outside?A: 1、Indoor storage
Other lubricants should be arranged systematically for easy access. Use the ones that have been stored for a long time and should not be blocked by the new ones." The "first in, first out" principle reduces the chance of oil deterioration due to overstorage.
2、Outdoor storage
Makeshift tents or waterproof canvas can protect the barrels from the rain. It must be stored on a shelf more than ten centimeters above the ground to prevent damage by moisture. The oil drums shall be laid horizontally so that the two drums on the top of the drums are plugged in the same level. When the barrel must be placed with the barrel plug upwards, the bottom of one side of the barrel should be tilted with a wooden bar, and the two drums should be connected in a straight line parallel to the wooden bar, so that the water is far from the opening of the barrel plug.
3、A lot of storage
Large quantities of lubricating oil and grease are usually transported to the plant by cylinder trucks or trucks and then pumped into the storage tanks. Since unloading large quantities of lubricating oil can be dangerous, only trained operators can handle it. If stored outdoors, all openings in the storage tank must be checked for sealing. Cover the tank with canvas or tent to protect it from the rain. Oil cylinders located in warehouses or oil storage rooms must be kept away from steam pipes, heaters, or any equipment in the building that generates high temperatures. In addition, the oil cylinder should not be placed in the cold or temperature changes too much. All galvanized iron cylinders or pipes should not be used as storage lubricants as the additives contained in the lubricants may chemically react with zinc, causing sludge and serious contamination of the lubricants. In some cases, even indoors, moisture can condense inside the tank. The condensate can be drained from the drain valve at the bottom of the tank or the water can be pumped out. If the oil drum contains grease, the condensed water will float on the surface of grease and can be sucked away by a straw. In any case, the most important thing is to quickly remove the moisture, so as not to rust and contaminate the lubricating oil or grease inside the storage tank
Mistakes in lubricating oil use
Proper and reasonable selection of lubricating oil and grease can ensure the dynamic performance of the vehicle, improve the reliability of the vehicle and prolong the service life of the vehicle. However, in the actual use, there are many mistakes in the selection of lubricating oil and grease, resulting in serious adverse consequences.
1. Diesels use gasoline engine oil Oil is divided into gasoline engine oil and diesel engine oil. Although gasoline engine and diesel engine both work under high temperature, high pressure and high load conditions, there are still great differences between them.
First, diesel engines have a compression ratio more than twice that of gasoline engines, and their main components are subjected to much greater pressure shocks than gasoline engines, so some of the components are made from the same materials. For example, gasoline engine main bearing and connecting rod bearing can be made of soft and corrosion-resistant Babbitt alloy, while diesel engine bearing must be made of lead-bronze or lead-alloy with high performance, but these materials have poor corrosion resistance.
To this end, in the diesel engine oil to add more anti-corrosion agent, in order to use can be in the bearing bush surface to generate a protective film to reduce the corrosion of the bearing bush, and improve its wear resistance. Because gasoline engine oil does not have this anti-corrosion agent, if it is added to the diesel engine, bearing bush in use is prone to spots, pits, or even flake off, oil will quickly deteriorate.
In addition, the sulfur content of diesel than gasoline, the harmful substances in the combustion process will form sulfuric acid or sulfurous acid, together with high temperature and high pressure exhaust into the oil sump, accelerate the oil oxidation and deterioration, so in the diesel engine oil need to add antioxidants, make the oil alkaline. If there is acidic gas into, can play a certain role in the neutralization, do not cause oil too fast oxidation deterioration. Gasoline engine oil does not add this additive, so it is neutral. If it is used in diesel engines, it will deteriorate quickly due to the corrosion of the acid gas. Therefore, diesel engine oil must be used instead of gasoline engine oil.
2. Domestic cars use imported oilNow some people think that imported oil must be better than domestic oil, so in domestic cars, especially new cars, the use of imported oil, this often produces a lot of problems. Imported oil, for example, low viscosity, mostly can't adapt to the domestic demand for oil viscosity, combined with the domestic engine accessories material thermal expansion system and fit clearance of imported cars, and most of chinese-made engine no oil radiator, if imported oil, oil will dilute the oil pressure is low, even can not meet the prescribed work pressure, can't meet the needs of normal lubrication, the engine wear.
3. Blindly choose the grade of the lubricant The lubrication quality of lubricating oil is good or bad, directly related to the length of the service life of the engine, especially the new type of vehicle is very strict with the requirements of lubricating oil, choose what lubricating oil, when to replace, how to replace, etc. should be carried out in accordance with the provisions of the manufacturer.
When choosing engine oil, we should pay attention to both quality grade and viscosity grade. Firstly, the performance level should be selected according to compression ratio, displacement, etc. Then according to the temperature, load viscosity grade of the choice. Good oil ensures good lubrication, reduces wear and tear, prolongs engine life, and prolongs oil change cycle. In the choice of oil viscosity, in addition to temperature conditions, should ensure that the engine lubrication and sealing conditions, as far as possible to choose low viscosity oil, in order to save fuel.
4. Mix engine oilAll kinds of lubricating oils have the same base oil except for different viscosity grades. The difference lies only in the variety and number of ingredients added. Therefore, lubricating oil varieties and quality grades are generally divided according to the variety and quantity of added ingredients. Different kinds of lubricating oil additives can not be mixed, otherwise it may cause the additive in the oil chemical reaction, damage the lubricant due to the performance. With the continuous improvement of additives and formulations, some common oils have been developed, such as QE/CC, QF/CD and other lubricants, which can be used within the range of grades indicated. Therefore, whether the oil can be mixed, according to the requirements of the specification, the name of the oil, variety, grade. Accordingly, reasonable choose use level and appropriate brand, cannot mix at will use.
5. The higher the viscosity of the oil, the better To reduce wear on moving parts, the oil must be viscous enough to form an oil film between moving parts at all operating temperatures. However, the viscosity of the lubricating oil shall not be higher than the degree of influence on the engine starting, and the minimum friction shall be generated under continuous operating conditions. Using an oil that is too viscous can increase wear and tear on parts,This is because:
(1)Lubricating oil viscosity is too large, the flow is slow, although the oil pressure is high, but the flow of lubricating oil is small, lubricating oil can not be timely added to the friction surface.
(2)When the lubricating oil viscosity is high, the friction resistance between the friction surfaces of moving parts increases, which affects the engine's dynamic performance and fuel economy.
(3)Lubricating oil viscosity is large, then its circulation speed is slow, cooling and heat dissipation effect becomes worse, easy to make the engine overheat.
(4)Due to the slow circulation speed of lubricating oil, the frequency of passing through the filter is less, and it is difficult to timely clean out the worn down metal dust, carbon particles, dust and other impurities from the friction surface.
Therefore, do not use excessive viscosity of the oil, can not think that the greater the viscosity is better. Under the condition of ensuring lubrication, according to the temperature range when using, as far as possible to choose the viscosity of the lubricating oil. However, the wear has been more serious, the clearance has been relatively large engine, can be selected with slightly larger viscosity of the lubricating oil.
6. When the oil goes black, it goes badEngine oil is working under harsh high temperature conditions, easy to oxidize and deteriorate, produce acid synthetic polymer deposits, in order to cause damage to lubrication.
In addition, combustion exhaust gas into the crankcase can also contribute to oil oxidation deterioration. Therefore, the use of a certain time of oil will usually become black and degenerate, losing its due lubrication, but with the continuous improvement of lubricating oil quality, especially the promotion and use of thickening machine oil, oil blackening does not necessarily mean that the oil deteriorates. This is because the clean dispersant added to the thickening machine oil disperses the sediment on the parts into the oil, darkening the oil color. Whether it is deteriorated, should carry out the test of various indicators, according to the quality of oil change, reduce unnecessary wave fees. If protective agents such as YY 102 are added to the oil, it will also become black after a certain period of use. So black oil is not the same as bad oil.
7. Multiple lubricants are bestMultigrade lubricating oil (also known as multi-viscosity lubricating oil) has the properties of light oil at low temperature and heavy oil at high temperature. In the case of multistage lubricants, one multistage oil may replace several single-stage oils. Although multi-grade oils are suitable for extremely cold and warm seasons and heavy duty engines, diesel engines that do not have difficulty starting on cold days are generally recommended to use a single viscosity oil to extend the engine's service life. Therefore, do not assume that it is best to use a multi-viscosity oil.
8. It is better to add more lubricating oil than lessThe harm that engine oil is too little is well-known, because this some car owner is afraid of lack oil burning tile, the lubricant quantity that fills often exceeds bid. Excessive lubricating oil has many harms:
(1)Crankshaft agitation makes oil form a large number of bubbles and deterioration, increased crankshaft rotation resistance, not only increase engine fuel consumption, but also reduce engine power.
(2)As the oil along the cylinder wall to the combustion chamber, resulting in "oil burning", oil consumption increased, emissions worsened.
(3)It accelerates the formation of carbon accumulation in the combustion chamber and makes the engine prone to deflagration.
Therefore, more than less engine oil is a mistake, the general oil level should be kept slightly lower than the scale is appropriate.
Q: How many grades of fire-resistant hydraulic fluids are there?A: Since World War II, some technologies have evolved into safer alternatives to mineral oils. Some of them, such as PCBS, are no longer used for health and environmental reasons. The International Organization for Standardization (ISO) has now identified four major categories of fire-resistant hydraulic fluids (FRHFs), with codes for each category based on their chemical properties. HFA stands for high water content hydraulic oil; HFB stands for water-in-oil hydraulic oil; HFC represents water glycol hydraulic oil; HFDS represent synthetic or "anhydrous" types of hydraulic fluids, including synthetic esters.
HFA type hydraulic oils are called high water content hydraulic oils (HWCF), or 95/5 liquids, because only 5% of the oil is emulsified in water. Oil increases lubricity and corrosion resistance, but most of the liquid is water, so the advantages and disadvantages of water still largely represent those of HFA type hydraulic oils. For example, HFA hydraulic fluids are extremely refractory, but they must be operated with specially designed equipment. Therefore, they cannot replace mineral oils that operate in typical hydraulic equipment.
HFA type hydraulic fluids are widely used in steel mills and coal mines, where equipment is designed for HFA type hydraulic fluids. Traditional oil-based HFA types are still used, but they are gradually being replaced by synthetic fluids with better lubricity, compatibility and biological stability.
HFB type hydraulic oil is also known as emulsion. In this emulsion, water droplets are dispersed in the oil, making up most of the 60% water content. Compared with HFA type hydraulic oil, this hydraulic oil is more lubricity and rust resistance, and in some cases can achieve similar performance to mineral oil. When there is a fire, water can put it out.
HFB hydraulic fluids require constant maintenance to ensure safe and trouble-free operation. The system temperature needs to be kept low to prevent water from evaporating. Likewise, its stability needs to be checked frequently to maintain fire resistance. The HFB type hydraulic fluid is now less useful due to its cumbersome maintenance requirements and inherent instability.
HFC hydraulic fluids, or water glycol hydraulic fluids, are now the most widely used fire-resistant hydraulic fluids. The hydraulic fluid contains 35 to 45 percent water, and glycol acts as a viscosity enhancer similar to antifreeze and thickeners. Like HFB type hydraulic fluids, the water in HFC type hydraulic fluids also acts as a fire retardant, so it must be monitored and maintained at a certain level at all times. The typical characteristics of HFC type hydraulic oil are good lubricity and wear resistance. However, it will shorten the service life of ball roller bearings.
HFC hydraulic fluids can be used in most equipment designed for mineral oils, but pump speeds, temperatures, and pressures need to be adjusted. All water-based hydraulic fluids, including all HFC types, are incompressible. When running a hydraulic system, this incompressibility causes the pressure inside the system to rise very quickly. Such extreme pressure spikes can damage equipment components, so it is important to keep this in mind when choosing HFC fluids.
HFD type of hydraulic oil, this large category of hydraulic oil has several kinds, because the general does not contain mineral oil and water can be called synthetic. Phosphate ester hydraulic oils are the first member of the HFD family and are the most flame-resistant. But it is being used less and less, mainly because it is less environmentally friendly, less compatible, and more expensive. Phosphate hydraulic oils are still used in certain applications, such as aircraft manufacturing and power plants, because of their high spontaneous combustion temperatures.
Most of the phosphate ester oil is replaced by fat anti - combustion hydraulic fat anti - combustion hydraulic oil. Because it is organic ester, fatty acid ester anti-combustion hydraulic oil has a very good anti-combustion type, is now the most common TYPE of HFD anti-combustion hydraulic oil. They are well compatible with various system components, fully compatible with mineral oils and suitable for high pressure applications. In addition, due to their organic nature, the products have a good biodegradation ability, non-toxic and harmless, very environmentally friendly. Fatty acid ester flame-resistant hydraulic oils are more than twice as expensive as conventional mineral oils, so they are only used in situations where flammability and biodegradability are required.
Other types of synthetic fire-resistant hydraulic fluids are designed for specific applications. Anhydrous polyether fire-resistant hydraulic oils have long service lives and are very environmentally friendly. Silicone oils are used in key applications, but these other types of synthetic fire-resistant hydraulic oils are very expensive.
What hydraulic oil does the hydraulic equipment of high temperature open flame situation use
Fire-resistant hydraulic oil/fluid should be used in high temperature flammable situations. The fracking hydraulic oil/liquid subdivision is mainly as follows:
HFAE: Water-In-oil emulsion inflammable hydraulic fluid (water content > 80%)
HFAS:Water-based inflammable hydraulic fluid (water content > 80%)
HFB: Oil-in-water emulsion inflammable hydraulic fluid (less than 80% water)
HFC: Combustion-proof hydraulic fluid containing polymer aqueous solution (water content less than 80%)
HFDR:Ester type refractory hydraulic fluid
1、HFAE water-in-oil emulsion has high specific heat, good fire resistance, excellent cooling performance, low cost, harmless to human body and good adaptability to general non-metallic materials due to its water content of up to 80%. However, because it is aqueous solution, high steam pressure and poor lubricity, the service temperature should not exceed 50℃, and the system pressure should not exceed 7.0MPa. It is suitable for the static pressure hydraulic system of coal mine hydraulic supports and other hydraulic systems or mechanical parts that do not require recovery of waste liquid and do not require good lubricity, but require good inflammable liquid.
2、HFAS Water-based refractory hydraulic fluids, also known as high water-based fluids, usually consist of 95 percent water and 5 percent water-soluble chemicals. It does not burn, has no compressibility, has high heat capacity and thermal conductivity, and has good cooling effect. The operating temperature of the system is usually lower than that of the oil system. Low viscosity, quick deposition of dirt, low price (only 1/5-1/10 of the cost of mineral oil), non-toxic, pollution-free, easy to handle. The best use temperature in 4 ~ 50℃, too low temperature may freeze, too high, evaporation too fast. The lubricity of water is poor, so it should not operate at a system pressure higher than 7.0MPa. In addition, it in addition to and aluminum, magnesium, lead, zinc, galvanized steel (material), cadmium metal materials do not adapt, and cork, paper, butyl rubber, leather, most coatings and coatings are not adapted. Attention should be paid when using. It is suitable for low pressure hydraulic system and metal working machine which need inflammable liquid.
3、HFB Oil-in-water emulsion is composed of 60% mineral oil and 40% water. Fine water particles are dispersed in the continuous phase of mineral oil. Water is the fire-resistant component. Compared with mineral oil, oil-in-water emulsion has a relatively low lubrication performance, which limits its use in high pressure systems. Due to the water content and high vapor pressure, the maximum temperature it can use cannot exceed 65℃. One of the main problems of oil-in-water emulsion in use is its stability. Long-term standing, high temperature and pollution will cause phase separation, which will accelerate the premature damage of the pump. The main advantage of oil-in-water is that it can use the same non-metallic materials as mineral oil, including seals, hoses and paints. It is suitable for general metal materials except magnesium. Suitable for medium pressure and high pressure, high temperature and inflammable system in metallurgy, coal industry, etc.
4、HFC水-Glycol liquid is also an anti-fire hydraulic fluid with water as the anti-fire component. It consists of 30-55% water and 25-45% ethylene glycol, glycerol or its polymer, water-soluble thickener, antiwear agent, antirust agent, anti-foam agent, etc. The liquid has excellent flammability, high viscosity index, good stability and fluidity, and is a transparent true solution. It can use the same sealing materials and hoses as mineral oil, but is not compatible with zinc, cadmium, magnesium, silver and untreated aluminum, and cannot use leather or cork. Can soften ordinary paint, only on epoxy or vinyl paint. Glycol has a certain toxicity, should be prevented from entering the mouth, but does not harm to the body. Suitable for low and medium pressure hydraulic systems in metallurgy and coal industries.
5、HFDR Ester type synthesis of fire - resistant hydraulic fluid. This kind of anti - combustion hydraulic fluid has high spontaneous ignition point, low volatility, good anti - combustion, lubrication performance is comparable with the best mineral oil. It can adapt to most metal materials. However, due to its large polarity, strong solubility, usually mineral oil can adapt to the general non-metallic materials such as nitrile rubber, neoprene, asbestos rubber sheet, polyvinyl chloride plastic, plexiglass and vinyl paint it does not adapt, must be carefully selected to match the material. Ester type refractory hydraulic oil mainly has two kinds, one is phosphate type, the other is fatty acid ester type, phosphate ester type has a long history, the use temperature range is -50 ~ 135℃, suitable for metallurgy, thermal power generation, gas turbine oil and other high temperature and high pressure operation of the hydraulic system. However, it has been gradually replaced by fatty acid ester type inflammable hydraulic oil due to its poor hydrolysis stability, highly toxic hydrolytic products and great environmental hazards.
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