In-line Turbidity Meters

The term "turbidity" refers to cloudiness in a clear fluid. Turbidity meters are instruments for the detection of this cloudiness in water, chemicals, and refined fuels. They can be hand held, laboratory or in-line instruments. Here we will be discussing in-line turbidity meters specifically for quality control in refined fuels. In-line instruments can be inserted directly into a pipeline to monitor fuels in real-time.

In refined fuels, turbidity is generally caused by dissolved water. Less often, it can be caused by sediment. The presence of water can be caused by condensation on the line, often when hot fuels exiting a refinery cool down in the pipeline. It can also be caused by leaks at terminals; in transport such as trucks, rail and marine; at custody transfer points; or at airport hydrant systems.

Turbidity meter applications for refineries

When turbidity occurs in a pipeline, there will generally be a dispute as to the cause. Did it come into the line from the refinery, or did it appear at the terminal? By placing a turbidity meter on the outgoing line of a refinery, not only can disputes be resolved, but any off-spec batches can be caught and returned to the refinery prior to transport. As turbidity is often not detected until marketing, without a quality control point at the refinery, these fuels have to be reshipped back to the refinery at an extremely high cost.

Generally, in such an application, operators would want a meters on the incoming and outgoing lines to the terminal as well as from the refinery to insure that the contamination did not existing prior to the terminal or refinery, or that it wasn’t caused a by a leak in the terminal. In the figure below, "THA" indicates the presence of a turbidity meter.

An additional application at the refinery would be off the distillation column. Occasionally, an off-spec batch of an individual fuel may come of the distillation column. By placing turbidity meters along the column, any off-spec batches can be immediately returned to the column for continued processing and production in the column can be optimized.

In-line turbidity meter applications for pipelines

Much as with refineries, pipeline operators have an interest in insuring the quality of the refined fuels they ship. By placing meters at incoming pipelines to the terminal as well as outgoing lines, operators are able to determine the cause of any turbidity contamination.

In-line turbidity meter applications for aviation

The standard for jet fuel is clear and bright. And while there are many opportunities for fuel contamination throughout airport fuel distribution, most quality control is conducted visually. Turbidity meters can automate quality control at key points throughout airport distribution including unloading sites, tank farms, hydrants systems, and fueling carts and trucks. Such systems can easily be alarmed in order to prevent any contaminated fuels from ever reaching a plane.

KEY APPLICATIONS FOR IN-LINE TURBIDITY METERS

• Refinery outgoing line quality control
• Refinery distillation column
• Pipeline terminals
• Aviation