Hydraulic Fluid Selection Tips
To ensure that the hydraulic pumps that you purchase from us can reach the optimal operating status in the hydraulic drive system of your machinery, we give following tips about hydraulic fluid selection.
1. Operating Viscosity Range
In order to reach the optimum efficiency and service life, we recommend the viscosity of hydraulic fluid to be used for axial piston pumps at operating temperature should be within the following range:
Vopt=16-36 mm2/s
It is related to oil tank temperature (open circuit)
2. Viscosity Limit
Vmin=10 mm2/s
For short period, under 90℃ which is the maximum allowable case drain temperature
Vmax=1000 mm2/s
For short period, cold start
Attentions
1. To select the correct hydraulic fluid, you must know the difference between fluid operating temperature in the tank and ambient temperature.
2. You have to choose hydraulic fluid so as to ensure that in operating temperature range, fluid viscosity can be in the best Vopt. It is recommended that fluid with as high as viscosity grade should be used for any occasion.
Temperature Range of Hydraulic Fluid
tmin= -25℃
tmax= 90℃
Hydraulic Fluid Filtration
To guarantee the normal function of axial piston components, fluid's cleanliness should be at least Grade 9 of NAS1638 or ISO/DIS4406 18/15.
