Testing to prove the control of foaming in hydraulic oil by the addition of regular ‘top up’ has been completed by Techenomics Indonesia in response to customer demand. The testing has proved regular ‘top up’ minimizes danger of damage caused by excessive foaming and ultimately reduces costs by reducing oil changes and increasing equipment availability.
Foam is a collection of small bubbles of air that accumulate on or near the surface of the fluid. Foam is an efficient thermal insulator, so the temperature of the oil can become difficult to control. The presence of air bubbles in the fluid can lead to excessive oxidation, cavitation, and the reduction of lubricating properties of the oil and hydraulics system failure.
The causes of foaming are many, but the most common include water contamination, solids contamination, mechanical issues (causing excessive aeration of the fluid), cross contamination of the fluid with the wrong lubricant, contamination of the fluid with grease and too much antifoam additive, either by incorrect formulation or by incorrect reconstruction of the additive package.
Many companies have a problem with foaming in hydraulic oil and consequently regularly filter their hydraulic oil to extend lubricant life. After discovering that a lot of their clients were doing just this, Techenomics Indonesia decided to carry out testing to show how to control foaming and to see if aggressive filtration affects foaming tendencies.
Six clients took part in the testing including Hexindo, Pama, Thiess, SIS, Madhani and Liebherr. Results show that a 20% top up can reduce the foaming tendency to 87.5% (normal limit).
Future results of this study and subsequent research will be grouped according to unit, oil type, oil hours and normal operation condition. This grouping is done to classify the top up and so far the results vary, most likely caused by:
- Different units of large capacity and small capacity, which affects the load.
- Type of oil, the additive composition of the various brands is very influential on the oil resistance.
- Oil hours, use of long-term and short term will have a different impact on the performance of existing additive in oil.
- Abnormal operation conditions, over-heating, over-load, seal leaks and other.