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Bacteria in marine diesel fuel oil

Beware of the diesel bug - this complete guide

Bacteria in marine diesel fuel i.e. diesel bug is a consortium of organisms which live in the water in a fuel system and feed on the fuel. These bugs include bacteria, yeasts and moulds that live in the water phase and continuously feed off on the oil phase.

If microbial contamination is left unmonitored over time, it will cause increased dirty or blocked filters and damage to motor injectors. In the worst cases, they result in tank corrosion, engine failure, power failure on critical power assets, causing great expenses, damages and downtime.

These potential problems can be avoided with regular testing of your diesel fuel to identify and treat microbial contamination in its early stages.

Pro-actively manage your marine diesel fuel in this 3 step approach

  • Diesel fuel test kit - Step 7

    Test your fuel for bacteria

    All that is required to conduct a test is to take a sample from your fuel tank i.e. water only sample, fuel AND water, or fuel only.

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    Quick overview of bacteria test:

    For a detailed step-by-step guide on how to use the test kit, click here.

  • 450 X 230 Warning

    Interpret test results

    Test results are typically ready within 10-30 minutes. Learn to interpret what each test result implies for bacteria in your fuel.

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    Normal limits:

    If the test and control line are visible in all test windows. The test line is the right line and the control line is the left line. If a test line is missing it means that there is a contamination but if a control line is missing it means a failed test. A filed test needs to be redone.

    Warning or low contamination

     

    • 450 X 230 Normal limits

      Normal limits

      If the test and control line are visible in all test windows. The test line is the right line and the control line is the left line. If a test line is missing it means that there is a contamination but if a control line is missing it means a failed test. A filed test needs to be redone

    • 450 X 230 Warning

      Warning or low contamination

      If one of the test lines are missing on the right hand side of the test kit it means you have a low contamination or a warning. The test has a low and a high contamination side where the right side is the low contamination side. It then follows that the left side is the high contamination side. If one of the lines on the right hand side, low contamination, is missing you have a Warning and action needs to be taken. If you get a Warning result do the test again to confirm the result.

    • 450 X 300 Action required

      High contamination: Immediate action required

      The left side of the test is the high contamination side, if one of those lines are missing you have a high contamination in your tanks and an action is required. If two lines on the low contamination side is missing and no line on the high contamination is missing it is still considered to be a high contamination. Make sure that all the left lines are visible as they are the control lines and if one of them is missing the test has failed and needs to be done again. If the result is a high contamination do the test again to confirm the result before any action is taken.

  • Distillate Fuel Oil Treatment

    Treat according to test results

    If test results had indicated moderate contamination, remedial action is required - apply kill dose of Mar 71 and re-test in line with risk assessment. When high contamination is detected: Empty, inspect, manually clean fuel system. Apply kill dose of Mar 71 and polish fuel before use. Re-test in line with risk assessment.

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Diesel fuel test kits

  • 1600X900 Unitor Bacteria Test Kit for fuel

    Unitorâ„¢ Bacteria Test

    Product group: 663 Product number: 764493

    Unitorâ„¢ Bacteria Test detects microorganisms which grow in marine diesel fuel oil. A rapid, accurate on site test which requires no special facilities, equipment or skills, the treatment indicating results are delivered within 10 minutes. All that is required to conduct a test is a 15 mL sample of water from the tank to be tested or a 200 mL sample of fuel and water if less than 15 mL of water is available.

  • 1600X900 Easy Ship Water in Oil Test Kit

    Easy Ship Water in Oil Test Kit

    Product group: 663 Product number: 773155

    Maintain and protect equipment, whilst eliminating damage caused by water in oil. With an easy to read digital display providing instructions and water in oil test / analysis results, a five year (10,000 tests) battery life and built in memory for recording previous test results, Unitor DIGI Water in Oil Test / Analysis Kits have become a favoured test method worldwide for onsite and onboard testing.