This standard specifies methods to determine the thermal stability of hydraulic oil.
This standard is applicable to all kinds of hydraulic oils, of which the base oil is mineral oils and synthetic oil.
2 Normative References
GB/T 265 Petroleum Products-Determination of Kinematic Viscosity and Calculation of Dynamic Viscosity
GB/T 7304 Petroleum Products and Lubricants; Determination of Neutralization Number; Potentiometric Titration Method
3 Summary of Method
The specimen remains for 168h at 135℃ in the present of copper rod and steel bar catalytic agents. The thermal stability may be evaluated by analytic determination the specimen, copper rod and steel rod before and after the thermal test.
4 Apparatus and Materials
4.1 Apparatus
4.1.1 Thermotank of electroheat autoconvection: able to control temperature of 135℃±1℃; volume not less than 470mm×425mm×372mm.
4.1.2 Aluminum bath: structure is detailed in the drawings and the materials are A1-3 aluminium pigs.