Info Centre >> Fuel and Lube Oil Technical Manual >> 7. Lube Oil - Test Results >> 7.1 Key Condition Indicators for Lube Oils >> 7.1.3 Salt
Salt is an indication of sea water ingress. Salt makes water many more times corrosive to any system and remains in the lubricating oil even if the water has been driven off by heat, i.e. in an engine. Salt will cause permanent engine damage by catalysing corrosion by water of any strong acids that are present.
The salt itself can react with tin in bearing overlay materials forming very hard tin oxide flakes, scoring journals and bearing materials. When mixed with the combustion products of heavy fuels, it is also capable of causing damage, such as high temperature corrosion, erosion and guttering of valve seats.
The maximum limit for salt in oil is generally less than 50PPM, preferably zero.
