Varnish is widely accepted as a lubricant failure mode in many applications such as turbine, hydraulic and compressors. Non-detergent R&O oils are among the most susceptible to develop deposits. The image at the top of this post, shows the presence of varnish deposits in the bearing, shaft and gear surfaces of a compressor. These types […]
Due to the large reservoir sizes of steam and gas turbines, it is most common to change turbine oils based on their condition rather than time. The most widely used guideline for determining the end of the useful life of the oil is ASTM D4378. A common endpoint is when the oxidative stability or antioxidant […]
Turbine oil varnish has been a well-documented reliability challenge for power plants. Traditional oil analysis techniques have been ineffective at predicting the onset of deposit problems in turbine oils – often defined as varnish. This has led to the commercialization of several new analytical tests which measures oil degradation products and can be correlated to […]
Ideally, a power plant selects a turbine oil that provides long life, free of performance problems, clear indicators of when the fluid needs to be changed and is provided by a dependable, knowledgeable supplier. It is more difficult than it appears however to choose such a fluid. The most common turbine oil selection criterion is […]
