Why Test your Diesel Storage tanks???

Why Test your Diesel Storage tanks???

Stored diesel fuel will deteriorate over time and in several different ways. The most common is through water contamination (condensation). This is where water molecules can infiltrate the fuel molecules. Water then displaces the diesel fuel inside the diesel engine, increasing wear because of the lubrication's absence.
The infiltration of water encourages bacterial growth within the diesel fuel causing fine sediments and bacterial residues to form, these may eventually sink to the bottom of the tank resulting in filter blockage, fuel pump wear, diesel engine damage or engine shut down.
Water is the worst form of fuel contamination.

Ultra Low Sulfur Diesel

Since 2006, government mandates have forced a major change in the amount of sulfur in diesel fuel (ultra-low-sulfur diesel, or ULSD), a precedent to additional steps to lowering emissions of particulate matter from diesel engines. ULSD provides less energy, leading to lower fuel economy, and requires more costly crude oil resulting in changes to the refining process. The refining process necessary to achieve these standards also reduces the fuel’s lubricating properties by removing naturally-occurring lubricity agents in diesel fuel.

The problems will become more widespread as all marine, rail locomotive and non-road applications move to ULSD by 2014. The ULSD enables emission control technologies that are required on marine diesel engines in 2014 and for locomotives in 2015.

Changes in the Refining Process

Efforts to refine crude oil utilizing hydrocracking processes that provide ULSD while maintaining or improving the yield of fuels from a barrel of crude oil results in higher asphaltenes (the heavy "asphalt" component of the crude oil) not being maintained in solution. This results in stored diesel becoming dark, either brown or black, evidenced by the accumulation of a tar-like substance on the bottom of fuel storage tanks.

How the Contamination gets into the Tank
Microbial contamination can be introduced to the fuel tank in a number of ways. A fuel supplier, dis-tributor or filling station may have a contaminated storage tank. Contaminants may also be drawn in through tank vents as fuel is used from a tank and replaced with air. Note that it could take months for the contamination, as it resides in the water at the bottom of the tank and reproduces, to develop to the point where it actually results in discernable symptoms of fuel contamination.

Clogged and Slimy Filters. A manufacturer of the diesel engine may recommend you change your filter at 15,000 miles, or, in the case of equipment where operating hours are the standard of measure, 300 hours (or some other interval). You should have acceptable performance up to that point. If, however, you find your engine performance begins to suffer at some fraction of that time (5,000 miles, or 50 hours) and changing the filter seems to solve the problem, then you have a potential fuel problem. If the fuel filter is black, has course material on the outside of the filter media, and maybe covered with a slimy material, than you have a definite fuel problem.

Dark and Hazy fuel. Water gets into the fuel tank in many ways. It can come from the fuel supplier, drawn in through the tank vent as fuel is drawn out of the tank, with condensation changing moist air to droplets, or it cancome from bio-diesel, where water is a common problem. Hazy fuel is the result of water be-coming emulsified into the fuel.

Loss of Power and RPM, and Corroded, Pitted Injectors. Fuel flow being reduced by clogged and slimy filters, the degradation of the diesel fuel, and the sulphate reducing bacterial contamina-tion that creates acids all contribute to the compromise of engine components that clog and cor-rode injectors and compromise efficient engine operation.

Excessive Smoke and Soot from Exhaust. Compromised fuel causes a drop in the cetane number of the fuel, resulting in shorter combustion times for each cycle of the engine, and compromised engine injectors result in substandard spray patterns, all resulting in incomplete fuel combustion. The result is a visible increase in black smoke (unspent fuel) and soot being expelled from the exhaust and higher levels of soot being apparent in engine oil analysis tests. Soot in the motor oil shortens the oil’s effective life and increases engine component wear.