The Weakest Link in High Availability Power Systems

“If I had to choose only one ‘weakest’ point, it would be fuel-management – again, an area where human error (by doing little) will be the root cause.”

– Professor Ian Bitterlin – Leeds University and Critical Facilities Consulting Ltd.

Whether the tank is an on-site day tank, a combined storage and day tank or a terminal facility, they all face the same problem with diesel. Diesel is rarely delivered to site at a quality suitable to dispense straight into the equipment forcing operators to filter the diesel before use.

OEM recommendations today specify diesel at ISO codes 17/15/13 but injector manufactures say 12/10/8 if you want maximum lifetime of the equipment.

Water is often present in diesel – either delivered with the supply or as a result of condensation. Presence of water means diesel deteriorates after only a few weeks in the tanks.


The diesel in storage tanks goes through a lot of steps from the refinery to the storage tanks and along the way particle content increases, water content increases and traces from sludge and bacteria can be found in the diesel.

If the diesel is not maintained during storage you will consume inline filters on a daily basis and still struggle to keep diesel within specifications.

Failure to keep the diesel sufficiently clean and dry will result in failure in fuel pumps, injectors, corrosion and poor fuel economy. High consumption of inline filters and clogging of inline filters will be common.

For some generator applications, e.g. back-up generators in Data Centres, critical assets may be compromised if the diesel is too contaminated to keep the generator running.

Typical Diesel Contamination:

Water & Particles

Water and particles/dirt cause the main problems in diesel systems. While both will have a direct negative impact on the engine; water found during storage will also lead to bacteria growth which will quickly clog fuel valves, injectors and in-line pressure filters causing engine stop/ failure.

Common problems caused by water and particles in the diesel are: rust/ corrosion, cavitation, microbial contamination and abrasive wear. There is a direct correlation between the water and particle level in diesel and the lifetime of critical components such as injectors, fuel pumps and filters.

Asphaltenes, Paraffins & Resin

As a by-product of the refining process and a natural consequence of fuel degradation processes, modern diesel contains asphaltenes, paraffins and resin. These are commonly known as organic debris but in daily language are referred to as tar/asphalt, wax, sludge and diesel bugs.

Most of the organic debris are acidic and will cause corrosion of injectors, pumps and tanks. They will plug your injectors, affect combustion and eventually clog in-line filters. In short, they will ruin your engine.


Fuel Sampling and Analysis:

An integral element of any fuel management plan should involve periodic fuel sampling and analysis. When you need to be 100% sure that your fuels are not contaminated and that when required, your generators will not fail, Fleury Engineering provides a complete oil sampling, analysis and reporting service.

For mission critical systems, full assurance of fuel or oil quality is crucial to avoid downtime, environmental impact and the cost of system failure. While visual inspection is an important tool for monitoring fuel quality, careful sampling and laboratory analysis is essential to providing a full assessment of the condition of your oil.

Conformity to specification and contaminant levels can only be assessed through precise testing.

Fleury Engineering ensures the correct sampling of fuels and provides a full and independent laboratory analysis, via trusted expert partners.

Installation of permanent/ temporary fuel filtration and polishing systems:

Filtration/ polishing systems are the first line of defence in ensuring the efficiency and longevity of your mission critical systems.

Filter systems are mission critical in almost every industry, including the pharma & petrochem industries, critical data and telecommunications storage, utilities, process industries, marine and power generation.

Fleury Engineering specialises in the specification, design, supply, commissioning, decommissioning and maintenance of filtration systems. We partner with leading manufacturers, such as CC Jensen and Hydro Carbon Filtration to bring you the best products available on the market.

By combining the best products with our expertise and valued partnerships, Fleury Engineering can provide a filter for the smallest of systems on a diesel engine right up to an offline filtration system for a turbine.

Mobile fuel polishing service:

Maximum reliability only comes from maximum quality fuels. Water, sediment, and microbial contamination in fuels stored for a period of time are a common problem.

Fleury Engineering is at the forefront of fuel filtration and cleaning in Ireland.

We offer a technical cleaning process to remove water, sediment and microbial contamination from oil and hydrocarbon fuel in storage.

We have designed and built our own mobile fuel and oil filtration rig and can tackle tanks of any size and shape.

We can polish up to 20 tonnes per hour with filters as fine as 1 micron to ensure your fuel is in-spec on completion.

We can also carry out the internal desludging of your tank to ensure the cleanliness of your system. This process removes the sludge, water and sediment deposits on the base of your tanks.

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