truck would indicate water. In this instance, the fuel should not be used until a lab tests the sample. Another
example would be a pinkish color in JP-4; this could indicate commingling of MOGAS into the JP-4 or
contamination with DL-2. Again, the fuel should not be used until a lab tests the sample.
A standard laboratory analysis will detect product contamination through tests such as distillation,
existent gum, water reaction, color, FSII, flash point, Reid vapor pressure (RVP), freezing point, water
separometer index modified (WSIM), particulate contaminant, and American Petroleum Institute (API)
gravity. Upon completion of the laboratory analysis, the senior laboratory technician will complete all test
results and record them on the Petroleum Products Laboratory Analysis Report (Figure 1-1). This report will
indicate what tests were run, specification limits, and if contamination is present. The report will also assist
you in identifying the source of contamination. The key thing to remember is that oily gum indicates
It is evident that, in identifying a possible contamination problem, all test results must be considered and
cross-checked with each other. Never base a determination on one test result. When a test series indicates
contamination, immediately take two additional samples and run tests. Proper verification is of the utmost
Analysis of lab reports is a difficult task. All results must be considered together since generally no one
result will by itself be off-specification. For example, when the flash point drops, the initial boiling point (IBP)
will correspondingly drop. Many results are directly related.
PART C - COMPARE TEST RESULTS TO DETERMINE IF THE FAILURE IS
DUE TO CONTAMINATION
Causes of contamination and preventative measures:
Fibrous material. Fiber in products is usually the result of filter/separator elements that have just been
put into service without adequate circulation and/or have ruptured in use. Adequate circulation and/or
filter element changes will prevent this.
Sediment. Sediment is any foreign object or matter in the petroleum product. This usually consists of
metal particles from rusty pipes or lines and/or internal pump housing flaking off. Adequate settling in
bulk storage coupled with an aggressive tank cleaning/coating program will prevent most of the sediment
problem. Filter/separators will also help correct the problem.
Water. Water can come from condensation in a tank and/or leaking lines or tanks. Settling and filtering
can greatly reduce this problem.
Microbiological growth. This results from sloppy storage procedures when water bottoms are allowed to
accumulate. Microbiological growth, when detected, must be corrected immediately. It is controlled by
removing water from tanks, received POL via 8/S, constant QS via laboratory testing, and proper use of
Commingling. Commingling of small amounts of products occurs from interfacial mixture disposal.
Larger amounts are usually caused by operator sloppiness. An aggressive on-the-job training program
can help prevent large scale commingling. Interface volume mixture can be controlled by increased line
pressure, correct batching sequence, and proper disposal procedures. The lab should recommend which
tank to fill with the interfacial mixture.