Oil and Water

Rust

The presence of water in diesel fuel systems causes a variety of problems. Water causes steel and iron components to rust, forming loose particles of iron oxide. These rust particles can quickly clog fuel filters. Micron sized and smaller rust particles may pass though fuel filters to reach injectors, scoring surfaces and ruining fuel injection spray patterns.

Bacteria

Standing water at the bottom of a fuel tank provides an excellent environment for a wide variety of soil bacteria to flourish. These bacteria enter through tank openings and during dispensing. Fuel and water form an interface that provides a comfortable home where bacteria can feed on diesel fuel in a moist environment. These bacteria form a slime layer that often breaks free to rapidly clog fuel filters and disperse bacteria throughout the fuel system. A fuel filter that is plugged with bacterial slime will have a dark layer of wet gel on the upstream surface. Living bacteria pump out acids as a waste product, further corroding and damaging fuel system components.

Reduced lubrication

Finally, any water that makes its way through to the fuel injectors reduces the lubrication properties of the diesel fuel along the way. This leads to galling, premature wear, damaged injection tips, and further corrosion of sensitive fuel system mechanical components.

Where Does the Water Come From?

The Supplier? Fuel changes hands, and tanks, as much as 7 times before you, the end user, receives it.

Insecure Tanks Fittings? Although self-explanatory we hear a lot of stories of water in tanks that after investigation has come from loose filler caps, perished or missing gaskets, broken tank breather pipes, sounding pipes etc etc. Even overenthusiastic deck washing…. yes, really.

Condensation? As the tank heats during the day and cools at night the fuel expands and contracts expelling air and drawing it back into the tank, This moisture laden air readily condenses on the tank wall and falls to the bottom as free water. It is insidious, a very small amount every single day, worse on some days better on others but non the less it very slowly builds up on the bottom of the tank, this is made worse if the fuel contains Bio-Diesel (FAME). Bio Diesel is 30 times more hygroscopic than standard diesel meaning it readily absorbs water from the atmosphere. Depending on which country you are in, condensation is by far the biggest source of water.

Ashridge Engineering Series 100 / 110

The Series 100 Electronic Water Detector has been designed to detect and measure the depth of water accumulating beneath Furnace Fuel Oil and Diesel in storage tanks typically on naval vessels and other containers.

Operating on the conductivity principle, the control unit box contains the battery, the electronic circuit and sounder. The probe and its cable are connected to the box via a connector located on the uppermost surface of the box.

A power switch is not required as no current is drawn from the battery when probe is clear of a conductive fluid. There are no hazardous voltages at the probe and current is limited to safe levels.

Downloads

• CP4 Capacitance probe Datasheet