Knowledge Base

Hydraulic Oil Properties
Function Property
Medium for power transfer and control
  • Low compressibility (high bulk modulus)
  • Fast air release
  • Low foaming tendency
  • Low volatility
Medium for heat transfer
  • Good thermal capacity and conductivity
Sealing Medium
  • Adequate viscosity and viscosity index
  • Shear stability
  • Viscosity for film maintenance
  • Low temperature fluidity
  • Thermal and oxidative stability
  • Hydrolytic stability / water tolerance
  • Cleanliness and filterability
  • Demulsibility
  • Antiwear characteristics
  • Corrosion control
Pump efficiency
  • Proper viscosity to minimize internal leakage
  • High viscosity index
Special function
  • Fire resistance
  • Friction modifications
  • Radiation resistance
Environmental impact
  • Low toxicity when new or decomposed
  • Biodegradability
Functioning life
  • Material compatibility