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Testing Times For Used Lubricants
The lubricating oil used in a large marine engine is an expensive asset. Filling a modern crosshead diesel engine with sufficient reserves typically costs around $5 - $6.00 per hp for system oils. The oil in a 20,000 hp engine would therefore be worth over $100,000. What can the ships engineers do to preserve the value of this expensive asset?
There are 3 quite simple answers.
Firstly, good housekeeping. Ensuring that oil and fuel leaks are detected, the oil is centrifuged, filtered and generally cared for in a professional manner.
Secondly, by using a laboratory based analysis service. All the major oil companies offer this service usually branded with a catching name such as PFA (Mobil), Texlube (Texaco), Exxcare (Exxon/Esso). These are sometimes free, sometimes not. They are invariably accurate and provide the most complete snapshot of the oil's condition. By examining the wear metal content and particle morphology, the results can be used to infer the condition of the machinery as well as the oil. The word snapshot is used advisedly; the process works best if used regularly. In this manner it is possible to build a picture of what is happening. More often this picture tells as much of a story in the changes to various parameters as it does by examining the absolute levels as these can vary significantly from ship to ship. They are usually used sparingly with typical analysis intervals from 3 to 6 months depending on how critical the system is. Highly critical systems such as slewing crane bearings on North Sea oil production platforms are often analysed monthly.
The third method is to analyse the oil using equipment on board the vessel. Again most major oil companies can supply suitable equipment. The standard varies from simple pass/fail type tests through to sophisticated electronics providing laboratory grade results. Most offerings lie somewhere in between these two extremes. It is possible to measure many physical properties of the oils, Viscosity, Water content, TBN, Insolubles, TAN, Salt content etc but not for wear metals. This equipment can provide a useful and often accurate indication of the oil condition but not much information on the condition of the machinery itself. The advantage is that the results are available immediately and testing can be undertaken more frequently, for example weekly or after maintenance. It is for this reason that on board testing is often undertaken in conjunction with a laboratory based analysis service. With an early and quick indication of oil degradation it is often possible to save the oil charge and the machinery at little or no unnecessary cost.
So, you have 3 ways to care for your oil:
There are 3 quite simple answers.
Firstly, good housekeeping. Ensuring that oil and fuel leaks are detected, the oil is centrifuged, filtered and generally cared for in a professional manner.
Secondly, by using a laboratory based analysis service. All the major oil companies offer this service usually branded with a catching name such as PFA (Mobil), Texlube (Texaco), Exxcare (Exxon/Esso). These are sometimes free, sometimes not. They are invariably accurate and provide the most complete snapshot of the oil's condition. By examining the wear metal content and particle morphology, the results can be used to infer the condition of the machinery as well as the oil. The word snapshot is used advisedly; the process works best if used regularly. In this manner it is possible to build a picture of what is happening. More often this picture tells as much of a story in the changes to various parameters as it does by examining the absolute levels as these can vary significantly from ship to ship. They are usually used sparingly with typical analysis intervals from 3 to 6 months depending on how critical the system is. Highly critical systems such as slewing crane bearings on North Sea oil production platforms are often analysed monthly.
The third method is to analyse the oil using equipment on board the vessel. Again most major oil companies can supply suitable equipment. The standard varies from simple pass/fail type tests through to sophisticated electronics providing laboratory grade results. Most offerings lie somewhere in between these two extremes. It is possible to measure many physical properties of the oils, Viscosity, Water content, TBN, Insolubles, TAN, Salt content etc but not for wear metals. This equipment can provide a useful and often accurate indication of the oil condition but not much information on the condition of the machinery itself. The advantage is that the results are available immediately and testing can be undertaken more frequently, for example weekly or after maintenance. It is for this reason that on board testing is often undertaken in conjunction with a laboratory based analysis service. With an early and quick indication of oil degradation it is often possible to save the oil charge and the machinery at little or no unnecessary cost.
So, you have 3 ways to care for your oil:
- Good house keeping
- Testing in a laboratory
- Testing on board.
