Operating Hydraulic Fluids

How DYNAVIS®-formulated hydraulic fluids work

Balance volumetric and mechanical efficiency in hydraulic fluids

Fluids formulated according to the DYNAVIS® performance standard are multigrade fluids, i.e. fluids with a high viscosity index (VI). That means they keep a proper viscosity over a broad temperature range. The higher the viscosity index, the wider the working temperature range within this fluid.

The efficiency of a hydraulic fluid has two aspects:

  • The volumetric efficiency, which means the ability to transmit power.
  • The mechanical efficiency, which means the ability to flow.

Unfortunately, these two effects show trends in different direction.

Mechanical EfficienCy

High energy consumption because of high viscosity.

The system starts with a relatively high viscosity to ensure that the viscosity in the pump is still high enough and to result in guaranteed lubrication even under short time local maximum temperatures. This results in tube friction which costs power and creates heat. The viscosity decreases and the system heats up.

On the way through the system those losses of mechanical efficiency sum up.

Volumetric efficiency

Loss of power by internal leakage creates more heat

In the pump the fluid gets warmer again and the viscosity decreases. Now the risk of internal leakage occurs. Consequently, a faster operation of the pump creates even more heat, the power decreases and the energy consumption increases.

The right hydraulic fluid for every application

DYNAVIS® formulated hydraulic fluids provide the right viscosity over a broad temperature range. DYNAVIS® allows operation in a widened temperature range, increases power and decreases energy consumption.

To choose the right fluid, both demands — good power transmission and easy flow — have to be in balance. The choice depends on the setup of the whole hydraulic system.

Different pump types, the same effect

The described technical effects occur in every hydraulic system with any kind of pump type. Which of the efficiency factors is of more or less importance depends on the specific situation.

Depending on the whole setup, they have to be in balance. DYNAVIS® formulated fluids can provide the optimal balance between mechanical and volumetric efficiency in every piece of hydraulically operated equipment.

A rule of thumb

Take one viscosity grade lower than with a monograde fluid and choose a DYNAVIS® formulated fluid with a viscosity index of at least 160 or higher.

This is possible without any risk because DYNAVIS® formulated fluids keep their viscosity over a broad temperature range. Thus, you can achieve energy savings of up to 5-15% and have an efficiency increase of 30% too. This information is based on maximum test results with an excavator. (see our field test).

The only thing you have to do: change your hydraulic fluid!

Shear stability

But that's not all. Hydraulic fluid formulated with DYNAVIS® technology guarantees shear stability. This is very important because hydraulic fluids are subjected to high mechanical forces. DYNAVIS® formulated fluids keep their characteristics under the hardest working conditions.