Demulsifying additives: driving towards greater efficiency and cost savings

Water contamination silently destroys engines and hikes costs. Steven Lumley, technical manager at WearCheck, explains how demulsifying additives can protect fleets, extend oil life, and boost efficiency.

The transport sector is constantly seeking smarter ways to enhance fleet efficiency and reduce operational overheads. Condition monitoring specialist company WearCheck offers ongoing tips and advice to achieve these goals.

Lumley shares her insights into a proven but often underutilised solution: demulsifying oil additives. This forms part of her extensive guidance on the benefits of a wide range of oil additives.

“Demulsifying additives, which separate water from oil, play a pivotal role in protecting critical equipment, reducing maintenance costs, and ensuring seamless operations in high-demand environments,” says Lumley.

Water contamination remains a persistent threat to engines and hydraulic systems, especially in humid or high-moisture operating regions. Demulsifying additives mitigate this risk by breaking water-in-oil emulsions, allowing contaminants to be efficiently drained during servicing.

The effects of water on oil and the systems being lubricated are insidious. Water is one of the most destructive contaminants in almost all lubricants and applications: it attacks the base oil, the additives blended into the oil, and the mechanical systems being lubricated.

Water can hasten the oxidation of a lubricant, ultimately shortening its service life. It encourages the build-up of sludge and varnish, and causes metal parts to rust and corrode. Water can also deplete a lubricant’s film strength, making components more vulnerable to wear, while stripping the lubricant’s additives, which impacts performance and diminishes its ability to protect metal surfaces.

Many oils separate well enough from water on their own, but some base oils and additives are prone to forming a stable emulsion when water is present. This means they require the addition of a demulsifier additive.

Demulsifier additives prevent the formation of a stable oil-water mixture by changing the interfacial tension of the oil, so that water coalesces and separates more readily from the oil. This is an important characteristic for lubricants exposed to steam or water, allowing free water to settle out and be drained easily at a reservoir. Most engine, gear, hydraulic, and turbine lubricants are formulated with this additive.

To be clear, demulsifier additives do not stop water ingress into the oil, but instead allow water to separate out more readily, thereby limiting its destructive potential.

An interesting fact about this lesser-known additive is that the chemical compounds used to create demulsifier additives are actually from the same group of chemicals used to form stable oil-water emulsions in oil-water-based metalworking fluids and fire-resistant fluids – just in much lower quantities. That’s right: the same substances that demulsify can also emulsify if added in large enough amounts!

In summary, the key benefits of demulsifying additives include:

• Reduced wear and corrosion: cleaner oil minimises abrasive damage in engines.
• Extended oil life: longer drain intervals reduce the frequency of oil changes.
• Faster maintenance turnaround.
• Optimised fuel use: efficient lubrication leads to smoother engine performance and lower fuel consumption.
• Sustainability support: less oil waste and extended equipment life align with green fleet initiatives and environmental targets.

With clean oil flowing through every critical system, transport operators gain not only peace of mind, but also measurable operational improvements. Demulsifying additives are a smart, low-investment strategy with high returns – especially for fleet managers seeking dependable, data-backed maintenance outcomes.

For more information, visit www.wearcheck.co.za.