Long-life hydraulic fluids

LONG-LIFE HYDRAULIC FLUIDS

A Long-life hydraulic fluid may also be referred to as HV/HVI (high viscosity index) fluid. These products may be based on highly refined mineral base oils or even synthetic bases.

The key differences between a standard mineral hydraulic oil and a long-life product are:

· Higher viscosity index (rate of change of viscosity relative to temperature). Standard hydraulic oils typically have values around 100, whilst HV/HVI products are generally over 160

· HV/HVI products are more expensive than standard hydraulic oils

· They generally last 2-3 times longer than a standard hydraulic oil under the same conditions (TOST test ASTM D 943)

When evaluating a long-life product, the following parameters should be considered:

· FZG load test (ISO 14635, DIN 51350)

· Air release (ASTM D1401)

· Demulsibility (ASTM D 3247)

· Viscosity index (ASTM D 2270)

The key advantages of using long-life oils in a hydraulic system are as follow:

· Better cold start

· Superior operation at high temperatures

· Significant energy/fuel savings

· Faster cycle times (increased productivity)

· Less frequent oil changes (increased productivity, lower costs)