How Varnish on Bearing Surfaces Affects the Coefficient of Friction A practical tribology article for turbomachinery, journal bearings, thrust bearings, and lubricated sliding contacts In turbomachinery lubrication, varnish is often discussed as a cleanliness, oil degradation, or servo valve reliabilityproblem. But in rotating equipment, varnish is also a friction problem. When varnish deposits form on bearing surfaces, thrust pads,Continue reading "How Varnish on Bearing Surfaces Affects the Coefficient of Friction"

Directed Lubrication in Double Thrust Bearings — and What Varnish Does to These Critical Areas The image shows directed lubrication arrangements for double thrust bearings, designed specifically to prevent bulk oil from contacting the thrust collar. This is an important detail in turbomachinery because the thrust collar is a high-speed rotating surface. If excessive oil is allowedContinue reading "Directed Lubrication in Double Thrust Bearings — and What Varnish Does to These Critical Areas"

Repeatability and Reproducibility Calculations in Turbine Oil Analysis Turbine engineers sometimes take one oil sample from the same turbine reservoir, split it into two or three bottles, and send the bottles to different laboratories. The objective is simple: “Let us compare the laboratories and see which one is accurate.” Then the reports come back, andContinue reading "Repeatability and Reproducibility Calculations in Turbine Oil Analysis"

Turbomachinery Major Inspections and Turnarounds How Turbine Oils Must Survive Until the Next Planned Outage In modern power plants, LNG facilities, refineries, petrochemical plants, compressor stations, offshore platforms, and steel industries, turbomachinery is expected to operate continuously for years between major inspections. During this period, turbine oil becomes one of the most critical reliability assetsContinue reading "Turbomachinery Major Inspections and Turnarounds"

All Khash Practical Experiences in the Field From Machinery Lubrication to Turbine Oil Reliability, Varnish Control, Oil Analysis, and Bearing Failure Learning Introduction: Practical Experience Is Not Written in Certificates Alone In the lubrication and reliability field, knowledge does not come only from books, standards, certificates, or training courses. Real knowledge comes when theory meetsContinue reading "All Khash Practical Experiences in the Field"

Deeper Technical Review: All Synthetic Oil Types Used in Turbomachinery Synthetic oils are not one family. They are several different lubricant chemistries, each with very different strengths, weaknesses, compatibility limits, and turbomachinery applications. In turbomachinery, the word synthetic can include: PAO — Polyalphaolefin Synthetic esters PAG — Polyalkylene glycol Phosphate esters Polyol esters Diesters Alkylated naphthalenes SiliconeContinue reading "Deeper Technical Review: All Synthetic Oil Types Used in Turbomachinery"

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 oilContinue 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 isContinue 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 whyContinue 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. ButContinue reading "Read My Articles on LinkedIn Too"