Hydraulic oil
Hydraulic oils are hydraulic fluids made from mineral oils with additives that serve as agents for increasing corrosion protection, aging resistance and reducing scuffing.
Designation of a hydraulic oil HLP of the ISO viscosity class ISO VG 46:
Hydraulic oil DIN 51524: HLP 46
Kinematic viscosity
Pour Point
Cleanliness
Flash point
Total contamination
Filterability
Water content
Corrosion properties
Corrosive effect on copper
Aging test
Behavior against seals
Air separator capacity
Foam test
Density
Ash content
Neutralization number
Corrosive effect on copper
A ground copper strip is immersed in temperature and time under defined conditions in a fixed sample amount and heated. After the end of the test or after completion of the heating copper strip is taken from the sample and washed. The color of the copper strip is compared with standardized comparison strips.
Air separator capacity
Air separation is the time in minutes in which the air dispersed in the oil has been reduced to 0.2% volume at a certain temperature. At a test temperature of 25 C, 50 C or 75 C air is injected under pressure into the oil. After interruption of the air supply, the escape of the dispersed air bubbles from the oil is monitored by determining the density as a function of time. The period of time until the dispersed air fractions are reduced to 0.2% (V / V) is taken from this graph.
