Annual Turbine Analysis: Ensuring the Health of Your Turbines

For many industrial operations, turbines represent one of the most capital-intensive assets and their reliability hinges heavily on the health of the lubricant. While turbine oils can be engineered for an extended service life of 10 to 20 years, various stressors such as oxidation, thermal degradation, and contamination can compromise fluid integrity earlier.

Because the oil serves as the primary medium for cooling, lubrication, and contaminant suspension, its condition directly affects turbine performance and longevity. Routine monthly oil analysis provides baseline condition monitoring, but it is not sufficient to assess long-term degradation mechanisms.

A comprehensive Annual Turbine Analysis is essential for evaluating key parameters such as oxidation stability, varnish potential, and additive depletion. These advanced diagnostics enable predictive maintenance strategies and help mitigate the risk of unplanned outages and equipment failure.

10 BENEFITS OF AN ANNUAL TURBINE ANALYSIS

An Annual Turbine Analysis offers substantial value in terms of performance optimization, reliability, compliance, and cost control. Following are compelling benefits:

1. Prevents Catastrophic Failure: Early detection of wear, misalignment, imbalance, or cracks in components can prevent devastating mechanical failures that result in unscheduled downtime and multimillion-dollar losses.
2. Optimizes Efficiency & Output: An Annual Turbine Analysis can uncover degradation factors that reduce thermal efficiency and increase fuel consumption.
3. Extends Equipment Life: Identifying and addressing issues early allows for proactive maintenance that extends the lifespan of expensive turbine components.
4. Ensures Regulatory & Safety Compliance: Many facilities must comply with OSHA, EPA, NERC, and other safety/environmental standards. An Annual Turbine Analysis helps ensure that emissions, noise, and mechanical integrity stay within regulations.
5. Supports Root Cause Analysis: Data collected through an Annual Turbine Analysis can support investigations into past incidents or performance anomalies.
6. Reduces Insurance Premiums & Meets Audit Requirements: Some insurance policies or risk mitigation strategies require Annual Turbine Analysis reports. Thorough documentation of proactive maintenance can lead to lower premiums and better terms.
7. Enables Benchmarking & Trend Tracking: Comparing year-over-year data allows teams to track deterioration trends and forecast future maintenance needs. This data also supports long-term asset management and CapEx planning.
8. Enhances Planning for Scheduled Outages: Insight from an annual analysis allows the prioritization and scoping of work during scheduled shutdowns—ensuring advance preparation.
9. Justifies Investments in Upgrades or Retrofits: An Annual Turbine Analysis provides quantifiable data to support the ROI case for control upgrades, component replacements, or other updates.
10. Improves Overall Plant Reliability: Reliability-centered maintenance is only as strong as the data supporting it. An Annual Turbine Analysis plays a central role in maintaining high uptime and availability.

GETTING PAST THE ROADBLOCKS

Considering all these benefits, why don’t all power generation facilities opt for an Annual Turbine Analysis? Here are a few common reasons:

• Perceived High Cost: Management may view an Annual Turbine Analysis as nonessential or too expensive, especially when budgets are tight. However, short-term cost avoidance often leads to long-term failure and major expense.
• Downtime Concerns: Even brief turbine shutdowns for inspection may be seen as disruptive to operations, especially in plants where uptime is critical. To avoid this, it’s best to schedule the Annual Turbine Analysis during planned downtime.
• A Reactive Maintenance Culture: In plants where the dominant strategy is Fix it when it breaks, there's often resistance to proactive or predictive maintenance investments. When it comes to turbines, this can be an expensive gamble.
• Aging or Scheduled-to-Retire Assets: For legacy turbines nearing end of life or scheduled for replacement, management may avoid investing in diagnostics. An Annual Turbine Analysis will be able to estimate just how much longer a turbine will continue to function optimally.

Despite the clear advantages of an Annual Turbine Analysis—from extending lubricant life to preventing costly unplanned outages—many facilities still hesitate to schedule this test due to perceived cost, downtime concerns, or a reactive maintenance mindset. However, these roadblocks often stem from short-term thinking.

By integrating annual testing into routine operations—especially during planned outages—even aging assets can benefit from critical insights into remaining service life. Ultimately, the cost of inaction far outweighs the investment in a proactive approach that safeguards turbine health and operational reliability.

 

THE TESTS

Annual monitoring of the oil’s physical and chemical properties, together with common contaminants such as water and solid particles, is essential. This thorough analysis is also recommended for new oils that must meet rigorous performance specifications prior to selection and use in a new application. The following tests/test methods should be included in an Annual Turbine Analysis:

• Acid Number; ASTM D974: Acid Number (AN) is an indicator of oil serviceability. It is useful in monitoring acid buildup in oils due to depletion of antioxidants. Oil oxidation causes acidic byproducts to form. High acid levels can indicate excessive oil oxidation or depletion of the oil additives and can lead to corrosion of the internal components. By monitoring the acid level, the oil can be changed before any damage occurs.
• Color; ASTM D1500: The ASTM D 1500 color scale is used for contamination monitoring. If the fluid’s color is off specification, this can indicate contamination.
• Demulsibility; ASTM D1401: Demulsibility measures an oil’s ability to release water. Water shedding characteristics are important to lube oil systems that have potential to have direct contact with water. Demulsibility can be compromised by excessive water contamination or the presence of polar contaminants and impurities.
• Foam; ASTM D892: The tendency of oils to foam can be a serious problem in systems such as high-speed gearing, high-volume pumping and splash lubrication. Inadequate lubrication, cavitation and loss of lubricant due to overflow can lead to mechanical failure. This test evaluates oils for such operating conditions.
• FTIR; JOAP Method, TestOil Turbine Method: Every compound has a unique infrared signature. FTIR Spectroscopy monitors key signature points of a specific lubricant in the spectrum. These signatures are usually common contaminants and degradation byproducts unique for a particular lubricant. Molecular analysis of lubricants and hydraulic fluids by FTIR spectroscopy produces direct information on molecular species of interest, including additives, fluid breakdown products and external contamination. It compares infrared spectra of used oil to a baseline spectrum.
• Karl Fischer Water; ASTM D 6304 procedure C: Low levels of water (0.5%) are typically the result of condensation. Higher levels can indicate a source of water ingress. Water can enter a system through seals, breathers, hatches and fill caps. Internal leaks from heat exchangers and water jackets are other potential sources. When free water (non-emulsified) is present in oil, it poses a serious threat to the equipment. Water is a very poor lubricant and promotes rust and corrosion in the components. Water in any form will cause accelerated wear, increased friction, and high operating temperatures. Non-emulsified water poses a serious threat to the equipment, leading to rust and corrosion. Emulsified water will promote oil oxidation and reduce its load handling ability.
• Membrane Patch Colorimetry; ASTM D7843: The Membrane Patch Colorimetry test is used to measure the color bodies of insoluble contaminants in lubricants. By monitoring the level of insolubles present in the lube oil, informed decisions can be made regarding the implementation of varnish mitigation technology and costly downtime avoided. Continued testing once varnish mitigation has been implemented can be used to help evaluate the effectiveness of the technology in use.
• Particle Count; ISO 4406: Using the Pore Blockage method, the sample is passed through a calibrated screen. As particles collect on the screen, the amount of flow decreases. This decrease in flow is measured and the particle count result is obtained. Higher levels of particulates in the sample may indicate machine health issues, a high rate of external particulate ingression or filter inefficiency. High levels of particulates can lead to accelerated machine wear due to abrasive conditions. Maintaining lower levels of particulates can increase the operational life of lubricated equipment.
• Rotating Pressure Oxidation; ASTM D2272: The Rotating Pressure Vessel Oxidation Test (RPVOT) is a test that determines the oxidation stability of an oil. RPVOT measures the actual resistance to oil oxidation whereas the other tests detect oxidation that is already present in the oil. Oxidation is a critical mode of lubricant degradation. As oil oxidizes it forms acids and insoluble oxidation products, which can lead to formation of sludge or varnish. These degradation products can coat bearing and oil cooler surfaces, preventing adequate cooling of the bearings. Areas with tight tolerances such as hydraulic control valves can also become coated causing operational issues.
• Ruler; ASTM D6971: Linear sweep voltammetry, more commonly referred to as the Remaining Useful Life Evaluation Routine (RULER) test, measures hindered phenolic and aromatic amine antioxidant content. This test quantitatively analyzes the relative concentrations of antioxidants in new and used oils in order to monitor the depletion rates of the antioxidant protection package in the oil. Hindered phenols and aromatic amines are primary antioxidants used in many industrial oil and zinc-free turbine oil applications. By measuring the depletion and available reactivity of these antioxidant compounds while conducting other routine performance tests, the service life of used lubricants can be effectively monitored. The level of antioxidants present in the lubricating oil gives an indication of the ability of the fluid to resist oxidation. Regular monitoring allows the rate of depletion to be observed, and can be useful in determining remaining useful life so that informed decisions can be made regarding oil changes.
• Rust A; ASTM D665 procedure A: The Rust Preventing Characteristics Test (ASTM D665) is designed to measure the ability of industrial oils to prevent rusting under conditions of water contamination. The test can be performed with either distilled water or synthetic seawater. The test consists of stirring a mixture of 300 milliliters of the oil being tested with 30 milliliters of water, either distilled or sea water, at 140°F (60°C) for four hours. A special cylindrical steel test specimen made of #1018 cold-finished carbon steel is polished and then completely immersed in the test fluid. At the end of the four-hour test period, the specimen is removed, washed with solvent, and rated for rust. A lubricant's ability to prevent rust is crucial for systems which have significant risk of water contamination. Testing a lubricant to determine if it has the capabilities to protect against rust is vital for maintaining the health of ferrous components within the equipment. In addition, rust particles can act as oxidation catalysts and can cause abrasive wear in journal bearings.
• Spectroscopic Analysis; ASTM D5185: The Elemental Spectroscopy test uses a spectrometer to measure the levels of specific chemical elements present in an oil. Monitoring the concentration of metallic elements can provide important information regarding machine and lubricant condition. By monitoring wear metals such as iron, copper, tin and lead rates of wear can be observed and abnormal wear modes can be detected. Many contaminants have metallic components which can be monitored as well. Increases in contaminant metals such as silicon, aluminum and potassium can indicate ingression of dirt, coolant or process contaminants. Some additives also have metallic components. Monitoring additive metals can help indicate when a system has been topped off with the incorrect lubricant.
• Viscosity; ASTM D445: The single most important property of a lubricant is its viscosity. It is the measure of the oil’s resistance to flow (shear stress) under certain conditions. It is an important criterion in the selection of a fluid. At low temperature, excessive viscosity may result in poor mechanical efficiency, difficulty in starting and wear. As oil temperature increases, viscosity decreases, resulting in lower volumetric efficiency, overheating, and wear. Selection of the optimum fluid viscosity grade will provide the most efficient machine performance at standard operating temperatures, therefore minimizing lost time and energy and fuel costs for the operator.

The power generation sector presents unique fluid degradation challenges that have a direct impact on turbine reliability and long-term asset performance. Regardless of the energy source, effective turbine maintenance depends on accurate assessment of lubricant condition and system health.

Degraded oil compromises critical functions such as heat transfer, wear protection, and contamination control, leading to increased risk of failure. Together with regular testing throughout the year, an Annual Turbine Analysis enables condition-based decision-making and helps ensure turbines operate within optimal performance parameters.

To schedule an Annual Turbine Analysis or for more information on working with Eurofins TestOil for fuel analysis, oil analysis or training, please fill out the form below; visit https://testoil.com/company/contact-us/; call 772-696-4405; or email mary.messuti@et.eurofinsus.com.

About Eurofins TestOil

With more than 30 years of experience in the oil analysis industry, Eurofins TestOil focuses exclusively on assisting industrial facilities with reducing maintenance costs and avoiding unexpected downtime through oil and fuel analysis program implementation. As industry experts in diagnosing oil-related issues in equipment such as turbines, hydraulics, gearboxes, pumps, compressors and diesel generators, Eurofins TestOil provides customers with same-day turnaround on routine oil analysis testing.  For more information on partnering with Eurofins TestOil on oil analysis programs or training opportunities visit https://testoil.com. Contact: Mary Messuti 772-696-4405; mary.messuti@et.eurofinsus.com.

 

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