A study by tribology experts indicated a fivefold increase in the operating life for an engine by decreasing the water content in oil. This signifies the extent of damage that water can cause by contaminating the lube oil.
What lies undetected in plain sight can exert some of the most sinister effects on the engine’s components. Water molecules infiltrate fuel and lubricant systems largely through the air and inconspicuous leakage points. They emulsify in oil, invisible to the naked eye, going largely undetected by maintenance engineers and plant operators.
Water initially affects the components of the oil itself. Most oils are made up of a base oil and additive package. Under conditions of high pressure and overheating, which are common in an engine, water acts as a catalyst for the degradation of each of these:
Additionally, water reduces the viscosity of the oil, which further complicates the asset reliability management of the system.
Water is relatively incompressible compared to oil. This means pressurized situations, it will maintain its low viscosity, reducing oil film strength, which results in more component wear and tear. Also, when water is exposed to the high pressures in “load zones” near gears and bearings, it causes problems such as:
Dealing with water contamination is an integral part of the oil management strategy and involves two essential steps—detection and cleaning.
There are several filtration units, but these cannot remove all types of contaminants. For effective removal of the water from oil, high-efficiency, high-depth cellulose filters work the best. With their deeper path (as high as 114 mm thick) and the highly absorbing nature of their filter element, these filters are the most efficient and cost-effective solution for engine application.
If the contamination level is too high, additional solutions like a Centrifugal Separators, Vacuum Dehydration, and the Bottom Sediment & Water (BS&W) bowls can be used. Use of a high-demulsibility lubricant can also be an option for a more distinct separation of water from oil.
In a study done by Noria Corp., USA, it was learned that if you reduce the water level in the oil from 2500 ppm to 156 ppm, you effectively increase the machine’s operating life (measured in terms of the MTBF—Mean Time Between Failure) by up to 5 times!
Water can be regarded as the #1 enemy of the lube oil as it damages the oil by affecting its lubrication efficiencies. It further causes severe damage to the engine components by being the root cause of corrosion and friction. The consequent losses are huge.
Therefore, it is paramount that operators reduce water contamination as much as possible. Experts advise the use of holistic oil quality management as the right solution—that comprises online oil condition monitoring for the early detection of water ingress and a high-efficiency depth filtration system for effective removal of water from the oil.
