Hydraulic oil is one of the main products of lubricating oil detection. The main role of hydraulic oil is to improve the performance of hydraulic equipment and prolong the service life of hydraulic components. Therefore, its development and production is an important part of the development of hydraulic technology. At present, the detection of hydraulic oil is generally based on the national mandatory standard GB 11118.1-2011. GB 11118.1-2011 divides hydraulic oil into five categories, namely L-HL, L-HM, L-HV, L-HS and L-HG, according to its use, which are respectively anti-oxidation and antirust hydraulic oil, anti-wear hydraulic oil (high-pressure and ordinary), low-temperature hydraulic oil, ultra-low temperature hydraulic oil and hydraulic guide rail oil. The largest output of hydraulic oil in China is HM oil. The viscosity brands mainly produced are HM32, HM46 and HM68. A small amount of HM22, HM100 and HM150 are produced. Due to the huge demand, HM oil is gradually divided into (ordinary) anti-wear hydraulic oil and (high-pressure) anti-wear hydraulic oil. For HV, HS and HG oils with small output, HV46, HS32 and HG68 viscosity grades are mainly produced. Although the production proportion of HV oil and HS oil is small, with the increasing demand for high-grade hydraulic oil, HV and HS base oils represented by high viscosity index and high-performance hydraulic oils are believed to have certain development space in future applications. For the enterprises using hydraulic oil, the selection of hydraulic oil must be based on the environment, working conditions, oil performance and economy. Different environments and working conditions require different hydraulic oils.
Use of HL oil and technical test indexes HL oil is mainly used in medium and low pressure hydraulic systems, such as precision machine tools. It can also be used for oil bath non circulating lubrication system of light load machinery requiring long oil change period. The test technical indicators of anti oxygen and anti rust hydraulic oil mainly include: density, chroma, appearance, flash point, kinematic viscosity, viscosity index, pour point, acid value, moisture, mechanical impurities, cleanliness, copper corrosion, liquid corrosion, foam property, air release value, sealing adaptability index, anti emulsification, oxidation stability, rotating oxygen bomb, and wear spot diameter. When the pressure of the hydraulic system is lower than 6.3 MPa, the hydraulic medium can be oxygen resistant and rust proof hydraulic oil. Use of HM oil and technical test indexes HM oil is used in medium and high pressure hydraulic systems, such as the furnace top machinery of various smelting furnaces of metallurgical machinery, as well as other medium load mechanical lubrication parts. The testing technical indicators of anti-wear hydraulic oil (ordinary) mainly include: density, chromaticity, appearance, flash point, kinematic viscosity, viscosity index, pour point, acid value, moisture, mechanical impurities, cleanliness, copper corrosion, sulfate ash, liquid phase corrosion, foam property, air release value, sealing adaptability index, demulsibility, oxidation stability, rotating oxygen bomb, FZG gear wheel test, vane pump test, and wear spot diameter. Test technical indicators mainly include: density, chromaticity, appearance, flash point, kinematic viscosity, viscosity index, pour point, acid value, moisture, mechanical impurities, cleanliness, copper corrosion, sulfate ash, liquid corrosion, foam property, air release value, sealing adaptability index, demulsibility, oxidation stability, rotary oxygen bomb, FZG gear wheel test, wear spot diameter, dual pump test, hydrolysis stability, thermal stability, filtration Shear stability. HM (common) (common anti-wear hydraulic oil) can be used for the hydraulic medium under the pressure of 6.3 MPa~16.0 MPa; When the pressure is higher than 16.0 MPa, HM (high pressure) (high pressure anti-wear hydraulic oil) can be used. HV or HS oil use and technical test index HM oil and HS oil are hydraulic oil products used in low temperature working environment, such as elevators, crushers, piercing equipment and special mine transport equipment in mining machinery. Especially in cold regions, where the ambient temperature is below - 15 ℃, low temperature anti-wear hydraulic oil HV or HS should be used to ensure that it is easy to start at low temperature and reach normal working temperature quickly. The test technical indicators of L-HV cryogenic hydraulic oil and L-HS ultra-low temperature hydraulic oil mainly include: density, chroma, appearance, flash point, kinematic viscosity, low-temperature viscosity, viscosity index, pour point, acid value, moisture, mechanical impurities, cleanliness, copper corrosion, sulfate ash, liquid corrosion, foam property, air release value, sealing adaptability index, demulsibility, oxidation stability, rotary oxygen bomb, FZG gear wheel test Wear spot diameter, double pump test, hydrolysis stability, thermal stability, filtration, shear stability. When the ambient temperature is - 5 ℃~- 25 ℃, HV low temperature hydraulic oil can be used; When the ambient temperature is - 5 ℃~- 40 ℃, HS ultra-low temperature hydraulic oil can be used. Use of HG oil and technical test indexes HG oil is used for machine tools with hydraulic and guide rail lubrication systems, as well as other mechanical lubrication parts that require good viscosity and lubricity. The inspection technical indicators of L-HG hydraulic guide oil mainly include: density, chroma, appearance, flash point, kinematic viscosity, viscosity index, pour point, acid value, moisture, mechanical impurities, cleanliness, copper corrosion, liquid corrosion, saponification value, foam property, sealing adaptability index, demulsibility, oxidation stability, FZG gear wheel test, wear spot diameter, and viscosity slip characteristics. The current GB 11118.1-2011 standard refers to the international standard ISO11158 - 1997. However, this international standard has been upgraded to ISO 11,158-2009 Specifications for Lubricants, Industrial Oils and Related Products (Class L) - Group H (Hydraulic System) - HH, HL, HM, HV, HG Varieties. A large number of enterprises have investigated and found that ISO 11158-2009 is not all applicable to the current industrial technical requirements, for example, the T6H20C double pump test indicators of L-HM (high pressure), L-HV and L-HS need to be determined according to the actual production situation in China.
