AN INTRODUCTION TO LUBRICANT SAMPLING, ANALYSIS AND TEST IN PREDICTIVE MAINTENANCE
PART BY JEFFREY CASCIANI-WOOD HONFIIMS
Lubricants are the life blood of all machinery and as an important element of predictive maintenance technologies, in service oil sampling, analysis and test can provide, inter alia, trace information about machine wear condition, lubricant contamination and general condition. Marine surveyors, using oil test analysis results, can make important maintenance decisions among which are the immediate benefits of avoiding the mixing of oils, contamination control, condition based maintenance and failure prediction.
Condition Caused
Contamination:
There are three major Condition Caused Contaminations that are formed within the lubricating oil during normal use and these are:
ACID:
These contaminants are formed when solid and moisture contamination are present and certain operating conditions exist within the engine. They can be controlled by the use of additional filtration and adding new make up oil at the service of the UF by-pass filter.
In most forms of fuel for
internal combustion engines, trace amounts of sulphur are present. Sulphuric acid is formed within the lubricating oil when sulphur molecules react with oxygen in the combustion chamber to form sulphur oxides.
These are then
blown past the rings and enter the oil. Here the sulphur oxides mix with moisture to form the highly corrosive sulphuric acid.
It is next
to impossible to remove trace amounts of sulphur from fuels by filtration. However, it takes two components to make the sulphuric acid, sulphur oxides and water. By using UF By-Pass filters that utilize absorbent type filter media, such as cellulose (paper) or cotton, the TBN (Total Base Number) of the oil stays up and the TAN (Total Acid Number) remains low.
• acid, • oxidation, • nitration.
The combustion by-products formed by burning diesel fuel, sulphur oxides and water, readily combine to form sulphur based acids. The bulk of these corrosive acids is removed as part of the engine’s exhaust but some remain
38 | The Report • June 2017 • Issue 80
2
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80
