U.S. Government Supply Source. If your ship is
another form of testing is required. All fuels should have
receiving fuel from a U.S. government supply source,
a clear and bright appearance. Your sample will have a
clear appearance when solids are not present. Your
the only required tests you must perform are the visual
sample will have a bright appearance if there is no free
inspections (samples) and the three BS&W tests
water present.
discussed in the preceding paragraph.
CONDITIONS AND FREQUENCY. There are
Non-U.S. Government Supply Source. If your
many conditions for which you will be required to take
ship is receiving fuel from a non-U.S. government
F-76 samples. During a refueling evolution, for
supply source, you must send a representative (if
example, you must sample F-76 from the deck
possible) to the supplier to witness the gauging,
connection at the beginning, middle, end, and every 15
sampling, and laboratory analysis of the fuel. At a
minutes until the evolution is completed. After sampling
minimum, your ship's representative should observe
F-76, you may determine that additional tests are
while the fuel is being tested for flash point, API gravity,
needed. Any time you prepare to test F-76, of course,
and BS&W. The flash point, especially, must be
you must first obtain a sample. For this reason, we will
determined before your ship can be authorized to receive
continue our discussion of sampling requirements in the
the fuel. You must determine the API gravity and BS&W
following section on fuel testing.
of the transferred fuel.
Testing
BS&W TEST. You will routinely perform the
BS&W test to determine the sediment and water content
You will routinely use the following tests to check
in your ship's fuels. Sediment and water are often
the quality of your ship's fuels:
present in heavy fuels. Too much water and sediment in
a fuel can cause blockage in the spray nozzles and poor
BS&W test
combustion of the fuel. In a fuel sample, the maximum
API gravity test
allowable percentage of BS&W is 0.1 percent.
Flash point test
To determine the BS&W, you will need a standard
sample bottle, two 100-milliliter (mL) centrifuge tubes,
Water contamination tests
and a centrifuge. Use the following steps:
We will describe these tests in the following paragraphs.
1. Use the standard sample bottle to obtain the
First, however, let's look at some of the conditions that
sample. The temperature of your sample must
will require you to perform these tests. After we explain
not be below 60F (15.5C).
the requirements, we will describe each of the tests,
using F-76 as a typical fuel sample.
2. Thoroughly agitate the sample. This is an
important step for accurate readings. You must
REQUIREMENTS AND CONDITIONS. As a
thoroughly agitate your sample before you
GSM assigned to the oil lab, you should be able to
continue to the next step.
recognize when you will need to perform routine tests
and when you will need to use additional tests to check
3. Measure exactly 100 mL of the sample into each
the fuels your ship receives. You will perform routine
of the two centrifuge tubes and tightly cap both
tests during a refueling evolution. You must, however,
tubes.
recognize the different requirements for when your ship
4. Place the tubes on opposite sides of the
receives fuel from a contracted U.S. government supply
centrifuge and whirl for 10 minutes at
source or a non-U.S. government source. In the
approximately 1,500 rpm.
following sections, we will explain these requirements.
5. After the unit has completely stopped, remove
Refueling Evolution. In addition to the visual
each tube, read the volume of water and
sampling requirements previously mentioned, you must
sediment at the bottom, and record the results.
also perform a BS&W test on the samples taken at the
start, midpoint, and end of the refueling evolution. The
6. Place the tubes back in the unit and centrifuge
sampling procedures and BS&W tests are routine testing
for 10 more minutes.
requirements. If at any time during refueling you
7. Again, remove the tubes (when the centrifuge
discover free water in any of the samples, stop receiving
has stopped rotating) and read and record the
the fuel until you can locate the source of the
results.
contamination and correct it.
