Turbine Oil
Turbine Oil Testing
Turbine Oil Testing
Turbine lube-oil systems are designed to cool bearings, flush contaminants away from rotating parts, prevent leakage of gases, provide hydrostatic lift for shafts and actuating valves in the hydraulic circuit and protect lube-system internals. Turbine oil formulations must handle large temperature fluctuations and the ingression of contaminants such as dirt and water. Monitoring in-service turbine oil condition for deterioration and degradation can significantly extend the life of both the lubricant and the turbine
The key to efficient turbine maintenance is routine monitoring of the oil, which ensures that decisions involving the turbine, including scheduling of oil changes and other maintenance, are based on what is actually happening inside the unit, instead of the number of hours, days or years of operation. Routine and in-depth monitoring can provide warning signs early enough to take corrective action.
What is Lube Oil Varnish?
Varnish is an insoluble film composed primarily of organic residue that coats the internal components of machines lubrication systems. Often comprised of degradation products associated with oxidation or thermal degradation, these soft contaminants are less than 1 micrometer in size.
Causes of Lube Oil Varnish
Oxidation
Thermal degradation
Varnish Potential Analysis
Varnish is an insoluble film that coats the internal components of machinery lubrication systems. The specific lubricant degradation byproducts associated with varnish formation remain elusive so is the need for the special test for finding the VPI ( Varnish Potential Index).
Petrolab offers two packages for turbine oil testing – PEAS – Turbine Oil Quality (Annual) PEAS – Turbine oil monitoring ( Quarterly) confirms to ASTM D4378
Benefits of Varnish Potential Analysis Testing
- Alerts customers of developing lube oil varnish problems
- Measures oil’s propensity to drop out varnish deposits
- Promotes proactive maintenance and contamination control
- Provides turbine users confidence at start up
Damage Done By Lube Oil Varnish
Reduced clearance zones affecting lubrication regimes
Often, this means a transition from hydrodynamic lubrication to boundary lubrication, which increases wear rates of pumps, bearings and gears.
Increased friction in components
Higher operating temperatures
Varnish acts as an insulator, lowering the effect of heat exchangers and lessening the ability of the lubricant to cool. The impact of friction and reduced clearance zones also contribute to higher temperatures
Restriction or impedance of oil flow
Varnish can cause valves, strainers and filters to clog.