Home » Part 1: Contaminated Hydraulic Oil
In this special two-part series, we look at contaminated hydraulic oil and the importance of proper filtration. Why is this important to you? If you’re running hydraulic machinery, the oil has a huge impact on performance. Small amounts of contamination impacts performance and can damage components. Put simply, good oil management will save you money.
While the core technology remains much the same as the early hydraulics invented in the late eighteenth century, we have fine-tuned modern hydraulic equipment to run at higher pressures and with finer tolerances to deliver greater performance and power than ever before. The oil is the medium that flows through the system, and if it becomes contaminated under these much greater loads, the potential for costly damage increases with it.
Hydraulic oil is an overhead for your business. While frequent oil changes will help the system run smoothly and protect critical components, it’s an expensive way to go about it. When we also factor in hydraulic oil disposal, there are compliance, safety and environmental considerations, which also come at a cost. It’s good business to get the most use out of your oil and better for the environment.
Hydraulic oil keeps all the parts of the machine operating smoothly. As we have discussed in our article about hydraulic fluid, we use different fluids for different applications, like high speeds and operating temperatures.
Contamination is the introduction of any other substance to the oil that prevents it from performing to the expected specifications. This includes contaminating particles, liquids or any other substance that effects the lubricating properties of the oil.
In many cases, an observant machine operator will spot loss of performance in machinery or unusual behaviour, which would point to contamination. Regular visual checks will also detect dirt or particulates in the oil. However, your oil can get contaminated with particles too small for the human eye, which can be equally as damaging. It comes back to machinery operating under higher pressures and with finer margins for error.
Contaminants come from the ground you’re working on, air, water, chemicals and even from within the system itself. Even if your oil looks clean, it may be contaminated.
Solids contaminants include:
> Dirt and dust in the air.
> Soil and sand from the ground.
> Metal, paint and rust from the machine.
Liquid contaminants include:
> Water from the environment.
> Excess grease or other oil.
> Diesel, petrol and other chemicals.
System contaminants include:
> Leftover particulates from machine manufacturing.
> General wear and tear from daily operation.
> Components out of alignment.
Air contaminants include:
> Air causing oxidation.
> Air pockets within the oil reducing compressibility.
> Air reducing lubrication.
These different forms of contamination have different effects on the machinery. In most cases, contamination has a snowball effect, where changes to and loss of performance degrade the machine and expose it to other forms of contamination. What seems like a minor issue can quickly spiral out of control, presenting safety issues for operators and unwanted delays in work.
Your hydraulic system within the machine should be tightly controlled and sealed. However, fluids, air, microscopic particles and internal issues can pass through seals and enter the system. Unfortunately, general operation itself also introduces contamination. Using a dirty container when refilling oil will introduce contamination. Cheap oil may not have a suitable purity rating for your machinery. Mixing hydraulic oil is also a recipe for disaster. Issues come from everywhere. Contamination is unavoidable and an issue all machinery owners need to know how to identify, remedy and mitigate with proper filtration.
In part two, we’ll cover those topics.