Author Archives: Khashayar Hajiahmad

Dry Gas Seals vs. Wet Seals in Centrifugal Compressors — The Critical Role of Turbine (Lube) Oil 1. How Lube Oil Interacts with Seal Systems (All Designs) In centrifugal compressors, the seal system is not isolated—it is deeply integrated with the lubrication system, especially in configurations where lube oil and seal oil share common reservoirs orContinueContinue reading “Dry Gas Seals vs. Wet Seals in Centrifugal Compressors — The Critical Role of Turbine Oil”

🔬 1. Fundamental Difference: Group I vs II vs III The key variables that control varnish behavior are: Aromatic content Polarity (solvency power) Saturation level Sulfur/nitrogen content ➤ Group I (Solvent Refined) High aromatics (~10–30%) Higher natural polarity Good solvency Lower oxidation stability 👉 Behavior: Keeps degradation products dissolved longer Forms varnish later, but when it forms → more sticky, heavy, darker ➤ContinueContinue reading “Group I,II,III Mineral Turbine Oils – Their Varnishing Behavior Difference”

Part-Load Operation and Accelerated Gas Turbine Oil Degradation: A Field Case Study Introduction A dual-fuel industrial gas turbine (natural gas and diesel), in service for approximately two years, was evaluated during a field lubrication survey. The unit was operating primarily under part-load and intermittent conditions, with frequent start-stop cycles and reduced injector demand. Although OEMContinueContinue reading “Part-Load Operation and Accelerated Gas Turbine Oil Degradation: A Field Case Study”

Strong Acid Number (SAN) in Turbine Oils — Formation Mechanisms, Field Reality, and Diagnostic Value 1. What SAN Actually Measures Strong Acid Number (SAN) quantifies strong, highly dissociated acidic species present in oil, typically expressed in mg KOH/g. These include: Sulfuric acid (H₂SO₄) Nitric acid (HNO₃) Hydrochloric acid (HCl) Strong acidic derivatives formed under severe conditions 👉 UnlikeContinueContinue reading “Why Strong Acid Number (SAN) in Turbine Oils is Ignored?”

Acid Number (TAN) in Turbine Oils – Everything You Need to Know 1. What Acid Number (TAN) Really Represents The Total Acid Number (TAN) is the amount of potassium hydroxide (KOH) required to neutralize acidic species in oil, expressed in mg KOH/g. From a turbomachinery perspective, TAN is not just acidity—it is a proxy for oxidation progression, additive depletion, andContinueContinue reading “Acid Number (TAN) in Turbine Oils – Everything You Need to Know”

❗ “Never Use NAS Again”? — A Technical Reality Check for Cleanliness Standards in Turbine & Hydraulic Oils 1. What You Saw in the Refinery: A Common but Outdated Practice Many large plants—especially refineries, power plants, and legacy oil & gas facilities—still report NAS values alongside ISO particle counts. This usually means they are using: NASContinueContinue reading “❗ “Never Use NAS Again”?”

When Oil Talks, Machinery Fails: Interpreting Turbine Oil Issues as Mechanical Failures 1. Introduction – Stop Treating Oil as a Lab Report In turbomachinery, lubricant condition is not a chemical curiosity—it is a direct mechanical signal. Too often: Oil analysis is treated as a trend chart exercise Mechanical teams wait for temperature, vibration, or trip events But inContinueContinue reading “When Oil Talks, Machinery Fails: Interpreting Turbine Oil Issues as Mechanical Failures”