Industrial lubricants to reach the service life must be replaced, if the use of industrial lubricants to scrap the standard, not only can not play a role in lubrication, but also damage to the machinery, the following to introduce the scrap standard of industrial lubricants.
1, viscosity, oil viscosity is too high, low-temperature start-up and pumping performance will be poor, the cycle cooling effect of the engine friction, wear will cause adverse effects. Viscosity is too low, oil lubrication ability to decline, will also increase wear. Therefore, the viscosity of scrap index most of the 100 ℃ motion viscosity changes in the range of not more than 20%-25%, there is no more than the oil of the SAE viscosity level. It is possible that due to the increasing degree of diesel engine and the dispersion of oil cleanliness, the upper limit of the viscosity of diesel engine oil is allowed to 35%.
2, insoluble matter, from pentane and benzene insoluble matter can generally judge the oil pollution. The limit content of oil insoluble material is quite different.
3, moisture, because the engine operating temperature range is very wide, oil into a small amount of condensate is unavoidable, may be cooling pump leakage symptoms. Therefore, the most commonly used oil moisture highest value of 0.5%, more than this value indicates that there may be free water.
4, neutralization value, the engine is most susceptible to acid corrosion of the parts is bearing. Tin or lead base bus alloys have good corrosion resistance, diesel engine bearings are more susceptible to corrosion copper-lead alloy, the original diesel oil acid value of the scrap standard set to 0.5. The use of oil containing additives, because some metal salts additives and potassium hydroxide chemical reaction, the new oil acid number is sometimes far more than 0.5 of the provisions. Therefore, the acid value of the used oil should be based on the oil additives and the number of changes to specify the maximum limit. or only the minimum reduction of oil used, but not the acid value.
5, flash point and fuel dilution, these two indicators are interrelated, but also significantly affect the viscosity of oil. Therefore, it is suitable for viscosity to consider as scrap indicators.