Author Archives: Khashayar Hajiahmad

100 Mistakes in Turbine Oil Analysis and Filtration That Can Cause Catastrophic Failures A. Sampling Mistakes Sampling from the drain valve onlyThis may collect settled sludge, water, or dead-zone contamination, not representative circulating oil. Sampling from stagnant linesA sample from a non-circulating point may hide active varnish, particle, water, and additive stress. Sampling cold oilContinueContinue reading “100 Mistakes in Turbine Oil Analysis and Filtration That Can Cause Catastrophic Failures”

Why It Happens and What It Means In turbomachinery, one of the most interesting and dangerous patterns is when the journal bearing vibration and bearing metal temperature do not increase smoothly, but instead show a repeated saw-tooth trend: temperature rises → vibration rises → sudden partial recovery → rises again → drops again → repeats This isContinueContinue reading “Saw-Tooth Pattern of Journal Bearing Vibration and Temperature in Varnished Turbomachinery”

Which Materials in a Turbomachinery Lubrication System Attract More Varnish — Chemistry, Metallurgy, and Surface Polarity In turbomachinery lubrication systems, varnish does not deposit randomly. It preferentially deposits on surfaces where the surface energy, polarity, temperature profile, flow regime, electrostatic condition, and metallurgy/oxide chemistry make the surface attractive to polar degradation products in the oil. This is whyContinueContinue reading “Which Materials in a Turbomachinery Lubrication System Attract More Varnish — Chemistry, Metallurgy, and Surface Polarity”

Dear friends and readers, Thank you for visiting my website and following my technical articles here. This website is my dedicated space for sharing deeper knowledge about turbine oil reliability, lubrication, oil analysis, varnish control, bearing failures, rotating equipment reliability, and practical field experience from power plants, oil & gas, petrochemical, steel, cement, and heavy industries. ButContinueContinue reading “Read My Articles on LinkedIn Too”

Khash MLE CertifiateDownload What Khash Learned Through Noria Machinery Lubrication Engineer Training and MLE Certification From Lubrication Knowledge to Lubrication Engineering Completing Noria’s Machinery Lubrication Engineer training and later achieving the ICML Machinery Lubrication Engineer — MLE certification changed my view of lubrication completely. Before this journey, lubrication could easily be seen as a technical activity: selecting oil, selectingContinueContinue reading “What Khash Learned Through Noria Machinery Lubrication Engineer Training and MLE Certification”

Turbine Oil Sampling Frequency and Test Scope ASTM D4378, OEM Practice, and a Practical Reliability-Based Approach In many plants, turbine oil sampling is treated as a calendar activity: monthly, quarterly, every six months, or yearly. But for turbine oils, the correct question is not only “how often should we sample?” The correct question is: What is theContinueContinue reading “Turbine Oil Sampling Frequency and Test Scope – ASTM D4378, OEM Practice, and a Practical Reliability-Based Approach”

I have always recommended MPC test patch photo to be included in the used turbine oil analysis reports. Turbine Engineer asked : Why MPC test patch photo should always be included in the report and not just MPC value ? Khash Replied: In turbine oil analysis, the MPC test is one of the most important tools for evaluatingContinueContinue reading “Why MPC Patch Photo and Patch Weight Should Be Included in Turbine Oil Analysis Reports”

Construction Details of a Servo Valve and How Oil Varnishing Affects Its Performance and the Hydraulic System 1. Introduction A servo valve is one of the most precise and sensitive components in a hydraulic control system. In turbomachinery, gas turbines, steam turbines, compressors, governors, EHC systems, hydraulic actuators, test rigs, and aerospace-type hydraulic systems, theContinueContinue reading “Construction Details of a Servo Valve and How Oil Varnishing Affects Its Performance and the Hydraulic System”

Artificial Intelligence in Turbine Oil Analysis & Filtration Where AI Can Help… and Where AI Should NEVER Replace Human Expertise The lubrication and turbine oil industry is entering a new era where Artificial Intelligence (AI), Machine Learning (ML), Industrial Internet of Things (IIoT), and predictive analytics are becoming part of reliability programs. For turbine oilContinueContinue reading “Artificial Intelligence in Turbine Oil Analysis & Filtration”