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Feb 23

How To Maintain Fuel For Diesel Generator Sets

By: Patti Dinneen


A majority of generator systems feature diesel engines. Unfortunately, stored diesel fuel can become contaminated over time, and using degraded fuel (or even simply leaving it in the generator when not in use) can damage the equipment over time.

Ultimately, this can mean that backup generators may not function properly (or at all) when needed. And a utility outage is not when you want to find out about the ill effects of poor fuel maintenance. The maintenance and testing of a generator's diesel fuel storage is essential, even more so for standby generator systems where the fuel may remain unused for months.

This blog post will briefly discuss the sources of fuel degradation, as well as what you can do to reduce your chances of fuel degradation.

What Are The Main Sources Of Fuel Degradation?

Gelling: This can be a problem this time of the year because diesel fuel freezes at a much higher temperature than most other fuels. Standard diesel can freeze at any temperature below 32 F, which will inevitably lead to gelling and/or clogged fuel pipelines.

Microbes: One of the threats of water is that it can harbor microbes, which create sediment that can pose a threat to filtration systems. These microbes can and do exist in fuel tank water bottoms.

Past Shelf Life: Like many products, diesel fuel has a certain shelf life and can begin to degrade after six months. After two years of inactivity, degradation can cause diesel fuel to become useless.  The degradation of fuel can affect other aspects of your generator, including flash and cloud points, distillation, and can also impair engine performance.

What Can I Do To Reduce Or Eliminate Fuel Degradation?

There are five main fuel services available to help you ensure that your diesel fuels allows the engine to run as necessary:

  • Fuel Filtering: A method that removes water and other contaminants. Our filtering system will filter contaminants off the bottom of your fuel tank and will remove water as well. The fuel is separated, filtered and returned to the tank; it is not required to waste the entire fuel supply! For more information on fuel filtering, click here.
  • Fuel Sampling: The fuel is checked to determine whether or not it is stable enough to handle a full load. Based on the results, other methods can be used to remediate any issues.
  • Fuel Treatment: With this service, we introduce additives to help correct and prevent future buildup of diesel contaminants. It is important to treat new fuel when it is added to your system, in order to prevent recontamination.
  • 50 Gallon Fuel Top Off: This service is used to help prevent condensation and reduce water in the system. By topping off the fuel, you can reduce sidewall services where condensation forms. If you add this step into your preventative maintenance program, you can reduce the amount of time you have to spend with a fuel vendor.
  • Fuel Polishing: Fuel polishing incorporates three major steps, which are designed in a way to fully ensure that your fuel is free from any bacteria and fungi. Fuel polishing helps to prevent a large percentage of diesel engine and backup generator failure because it removes microbial development, which is a major cause. You should incorporate fuel polishing into your annual planned maintenance schedule. To learn more about the process, check out this blog, "What Is Fuel Polishing."

These five fuel services should be incorporated into your planned maintenance schedule. If you have not taken the time to speak with a generator set serviceman, do so before any major issues arise.

Kinsley Power Systems

Our goal is to ensure that your system performs when you need it. Kinsley Power offers customized preventive maintenance programs and extended warranties for all customers - hospitals and cable companies and factories and homeowners alike. Kinsley services all major make and model generators, transfer switches, switchgear and PTOs. Kinsley also offers such specialized services as load bank and infrared testing.

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