Author Archives: Khashayar Hajiahmad

What Does 100 ppm of Water in 20,000 Liters of Turbine Oil Really Mean? In lubrication engineering, water contamination is typically reported in ppm (parts per million). While this number often appears small, it can be dangerously misleading if not translated into actual physical quantity and system behavior. Let’s convert 100 ppm into reality—and more importantly, into risk. StepContinueContinue reading “What Does 100 ppm of Water in 20,000 Liters of Turbine Oil Really Mean?”

Fleet Turbine Oil Criticality Analysis and RUL Estimation 1. Purpose The goal is not only to say: “This oil is bad.” The real goal is to answer: Which turbine oil system must receive action first, why, what action, and how long can it safely continue before forced oil replacement, varnish-related reliability risk, or equipment damageContinueContinue reading “Fleet Turbine Oil Criticality Analysis and RUL Estimation”

⚙️ 1. Baseline: What a Pure Turbine Oil Is (Without EP) A classical turbine oil is fundamentally an R&O (Rust & Oxidation inhibited) system: Highly refined base oil (Group I, II, or III) Additive package: Antioxidants (phenolic / aminic) Rust inhibitors Demulsifiers Anti-foam agents 👉 The design philosophy: Chemical stability > load carrying Low polarity system Minimal surfaceContinueContinue reading “⚙️Turbbomachinery with Gears – Turbine Oil With EP Additives – What is the difference in performance with normal Turbine Oils ?⚙️”

Turbomachinery Engineer Asked : We have speed factor in rolling bearings , what do we have for speed in journal bearings linked to oil lubrication ? Khash Replied: In rolling bearings, you’re used to the speed factor (n·dm) as a practical limit tied to heat generation and lubrication regime. For journal (hydrodynamic) bearings, the equivalent thinking is notContinueContinue reading “The Role of Rotational Speed in Hydrodynamic Lubrication: Interpreting Journal Bearing Performance via Sommerfeld and Hersey Parameters”

Aeroderivative Gas Turbines: Turbine Oil Selection and Lubrication Differences Versus Other Turbomachinery Aeroderivative gas turbines are industrial gas turbines developed from aircraft engine technology. They are compact, lightweight, high-power-density machines with very fast start-up capability. They are widely used in power generation, offshore platforms, LNG, pipeline compression, emergency power, mechanical drive applications, and peaking powerContinueContinue reading “Aeroderivative Gas Turbines: Turbine Oil Selection and Lubrication Differences Versus Other Turbomachinery”

Air in turbine oil is not a single condition but a spectrum of physical states that behave differently inside a lubrication system. At one end, air exists as dissolved gas, fully in solution within the oil according to thermodynamic equilibrium (Henry’s Law). Under normal pressure and temperature, turbine oils can hold a significant amount of dissolvedContinueContinue reading “⚙️ Air in Turbine Oil — Forms, Testing, Root Causes, and Corrective Actions”

Hopefully one day I would add photos, charts and all my field experiences and publish it. Now is just text. Please read and share it. Turbine Oil Reliability – TOR from Khash – FinalDownload Follow Khash LinkedIn ==> https://www.linkedin.com/in/khashayar-hajiahmad/ YouTube ==> https://www.youtube.com/@khashayar_Hajiahmad

🛢️ When MPC ΔL is High and the Patch Turns Black (Soot Formation & High-Temperature Degradation in Turbine Oils) 1. First – What Does ΔL Really Mean? In the ASTM D7843 MPC test, the L value represents lightness (white → black): High L → darker patch → more black particles (carbon/soot) Low L → lighter patch →ContinueContinue reading “🛢️ When MPC ΔL is High and the Patch Turns Black”

Gas Compressors – Interpreting MPC Patch Colors with Chemically Sound Accuracy This refined version keeps your powerful field insight—but aligns it with rigorous lubricant chemistry, so both engineers and chemists will agree with it. 1. What the MPC Test Actually Measures The Membrane Patch Colorimetry (MPC) test: Passes a diluted oil sample through a membrane Captures: insoluble particles borderline solubleContinueContinue reading “Gas Compressors – Interpreting Varnish Colors on MPC Patch Tests Based on Gas Contamination”

I asked : When Varnishing forms then secondary damage would be which form ? so some times after bearing failure happens it covers the real foot print of the primary root cause which is varnish ? Khash Replied : Your question is exactly where many failure analyses go wrong—because varnish is not just a “deposit,”ContinueContinue reading “You Didn’t Have a Wear Problem… You Had a Varnish Problem”