When the ambient temperature is less thanHydraulic oilIt freezes at the freezing point。The freezing point of hydraulic oil refers to the very high temperature at which the hydraulic oil terminates the flow under the required refrigeration standard, and is also a key quality standard。For example, the freezing point of HV hydraulic oil is around -60℃，If the ambient temperature is less than -60 ° C, condensation is likely，The freezing point of the locked hydraulic oil is closely related to the composition of the hydraulic oil，The key is prepared by mineral oil and synthetic oil from refined oil production and processing, adding appropriate amount of anti-wear reducing agent and other ingredients。Hydraulic fluids are also divided into many types according to their composition。Common types are HH, HL, HM, HR, HG, HV, HS are mineral oils。

        Not the same typeGansu hydraulic oilIts performance and efficacy are also very different at different ambient temperatures。The key in the hydraulic transmission system plays a variety of effects such as kinetic energy transmission, anti-wear, wetting, anti-corrosion and refrigeration。 Generally used hydraulic oil to meet the following quality requirements: 

            1, suitable viscosity and excellent viscose-temperature performance to ensure that hydraulic oil in different working temperatures will more accurately transfer the driving force and wetting the hydraulic system。 

            2, with excellent gas release value, foam resistance, water solubility and sealing adaptability。 

            3, with excellent rust treatment, air oxidation stability, fire resistance to hydraulic oil heat resistance and emulsion resistance。