Identify Lubrication Warning Signs: A Guide to Oil Analysis

Understanding the condition of lubricants is vital for uninterrupted plant operations. A robust oil analysis program tracks key wear indicators, compares them to historical data, and reveals trends. This approach uncovers contamination, lubricant degradation, abnormal wear, and sampling issues—transforming a time‑based program into a data‑driven, condition‑based strategy that cuts unnecessary oil changes.

Total Acid Number – This metric gauges the extent of oxidation that the fluid has experienced since startup. It is a reliable performance indicator and a strong predictor of when replacement is needed. As oil ages and is exposed to air, oxidation rises, diminishing lubrication effectiveness. A significantly higher total acid number than the baseline signals a critical warning. Particle count, another essential parameter, reflects system cleanliness and filter performance. Elevated particle levels—beyond the initial baseline—also warrant a lubricant change.

Water – Water is the primary enemy of lubricants, especially in humid or steam‑rich environments. Each lubricant type has a specified maximum water content, typically expressed in parts‑per‑million (ppm). For instance, polyalkylene glycol (PAG) tolerates higher water levels than polyalphaolefin (PAO). Supplier data provide the acceptable limits. Exceeding these thresholds is a clear red flag for impending lubricant failure.

Metals – Metal analysis reveals wear patterns and additive performance. Common tests target copper, aluminum, and iron—the metals most likely to be present in oil. As with water, each lubricant has a tolerance for metal content; suppliers can advise when results indicate a need for change.

Particle Analysis – Detects metal contamination and confirms that filtration is operating correctly. High particle counts often mean that the system’s filters are clogged or ineffective, shortening the interval between oil changes.

Viscosity – The simplest yet most telling test of lubricant health is its kinematic viscosity. By measuring viscosity over time, you can detect wear. A viscosity increase of more than 10 % typically signals that the oil should be replaced.

Many leading lubricant suppliers offer comprehensive oil‑analysis programs that monitor these parameters and predict optimal change times. Contact your supplier to find out if such a program is available.

About the author:

Phil Grellier is the Global Solutions Development Manager at Dow Corning Molykote. For more information, e‑mail phil.grellier@dowcorning.com or visit www.dowcorning.com.