To gain a competitive advantage, it is imperative to get the most out of your hydraulic fluid, Petro-Canada Lubricants’ Neil Buchanan* says.

It starts by selecting the right oil. This means not only using a high-performance hydraulic fluid, but choosing the correct viscosity for each pump and motor, as well as considering the temperature range the fluid must operate in.

For a mining operation, with the sheer range of equipment used – from 260 t haul trucks, to hydraulic shovels, front end loaders, right through to drills, bulldozers and cranes – and the tough conditions it is exposed to, there are a lot of individual components to consider and decisions to make; all the more reason to maximise the use of your fluid.

But it is not just about oil selection: what you do with the oil when the system is running can be equally important.

Running regular used oil analysis as part of a maintenance program can provide operators the opportunity to catch an impending failure before it becomes catastrophic. Unplanned downtime costs time and money; used oil analysis can help avoid it.

The basic principles

Used oil analysis enables operators to monitor and optimise the life of a system and its hydraulic fluid. Typically carried out in a simple three-stage process, used oil analysis involves taking a representative sample of the fluid, sending it to a qualified used oil analysis laboratory and then interpreting and acting on the recommendations of the results.

Most mines undertake used oil analysis, but, when incorporated into a reliability centred maintenance program, the process can enable lubricant technical service advisors and mine personnel to evaluate trends over time, which not only helps to get ahead of system failure but provides a basis for better informed maintenance decisions.

Monitoring key properties

Regularly monitoring the key properties within the hydraulic fluid can give an insight into hidden and potentially harmful contamination, invisible to the naked eye.

Viscosity, the fluid’s resistance to flow, is one basic property measured in used oil analysis. However, viscosity is a lagging indicator, proceeded by additive depletion and oxidation which increases the fluids acid number (AN). Acid number was previously referred to as total acid number (TAN).

Another property that should be regularly monitored is oxidation, which occurs when the fluid is exposed to high temperatures and air (oxygen) and is common in hydraulic systems. The rate of oxidation doubles for every 18°F increase from 150°F, which highlights the importance of hydraulic oil temperature to its life. The impact of oxidation is a darkening of the oil, an increase in viscosity and potential sludge, varnish and deposit formation.

Using the data

Perhaps the most important step – and the one that will give operators the greatest advantage – is to effectively manage and interpret the fluid data accrued from the analysis quickly to enable effective decision making. Digital diagnostics and customised asset management reporting are two of the tools used to secure rapid sample results. Utilising oil diagnostics keeps an operation one step ahead by using the latest technology to proactively track where maintenance is needed and predict where it will be needed in the future.

While used oil analysis is widespread among the mining industry, not every mine is using it to the full extent they could. Using oil analysis as a predictive tool can help operators ensure they get the maximum life possible from their hydraulic fluid and move away from time consuming, reactive maintenance.

*Neil Buchanan is Senior Technical Services Advisor for Petro-Canada Lubricants, a HollyFrontier business