EFFECT OF CONTAMINATION ON THE WATER SEPARABILITY OF STEAM-TURBINE OILS

The effect on water separability of three commercial steam turbine oil s when contaminated with engine oil and/or a commercially available en hancement additive (designated as Additive X in this paper) for automo tive lubricants was investigated. Additive X is an after market lubric ating oil supplement containing conventional crankcase type additives. All three oils showed degradation of water separability when contamin ated with as little as 500 ppm (the ppm unit used through out this pap er is ppm m/m.) of Additive X alone, as little as 500 ppm of engine oi l alone, or 300 ppm of Additive X and 300 ppm Of engine oil. It is spe culated that the contamination affects water separability because of i ts calcium-based detergent component. The contamination at these level s in the steam turbine oil is not easily detected by trace metal analy sis commonly used in rapid oil analysis programs. This is of concern b ecause Additive X and engine oil are often used in industry to coal be arings during turbine generator maintenance. This study indicates that such practices could result in unsatisfactory water separation charac teristics of the turbine oil.