What You Need to Know About Diesel Generator Fuel Testing

Jun. 19, 2024

Diesel standby generators offer a reliable and efficient power supply when you’re off the grid. Most of them act as a supplemental energy source and can sit unattended for long periods. As diesel fuel has a limited shelf life, it’s important to test the fuel regularly and maintain the fuel quality to ensure the smooth operation of your generator. In this article, we’ll introduce the importance of diesel generator fuel testing and how to test the diesel fuel quality.


Why is diesel generator fuel testing important?


Diesel generator sets usually use diesel fuel as their fuel source. Generally, diesel fuel can be stored for up to 6 months to 1 year without significant degradation if it’s stored in a clean, dry and cool environment. Please note that improper fuel storage of generator set will affect its normal performance. Factors such as heat, humidity, pressure and oxygen can affect the storage life of diesel fuel. Diesel storage exposed to extreme temperatures is more likely to degrade. For example, some diesel gensets used in tropical and subtropical regions are particularly susceptible to diesel fuel issues due to the wide range of temperature variations and the relatively high humidity. 


What You Need to Know About Diesel Generator Fuel Testing

When your fuel tank is not full, air will enter in the tank and build up water vapor during the cooler evenings. The water contributes to the oxidation of metal components as well as bacterial and fungal growth (microbes). Additionally, the degradation of diesel leads to sediment and particulates within the fuel tank over time. Sediment and sludge can clog filters, damage pumps, and lead to generator loss of prime and ultimate failure. Using such poor-quality or contaminated diesel will hurt fuel economy and performance, even cause emergency generator failure. 


Regular diesel generator fuel testing can help nip potential problems in the bud before they evolve into something far more severe. It ensures the fuel quality and maximizes the power output of your diesel generator. In addition, it can reduce emissions and environmental impact. It can also protect equipment by preventing corrosion, injector fouling, and wear caused by contaminated diesel, thereby extending the lifespan of the diesel generator. Regularly testing diesel fuel quality reduces maintenance needs, leading to operational cost reduction.


How often should generator fuel be tested?


Fuels stored for more than six months are subject to aging degradation - oxidative products, condensation buildup, and microbiological growth. Per NFPA 110 Part 8.3.7, a fuel quality test shall be performed at least annually using appropriate ASTM standards or the manufacturer’s recommendations. If you can, regularly test the emergency diesel generator every 6 months to ensure fuel quality and prevent engine damage.


How to test diesel fuel quality?


Generally, the diesel fuel testing assessments include water accumulation, sediment, bacteria and fungus buildup, bad contaminants and removable sludge, the quality of your generator's existing fuel supply and your power system's efficiency. You can choose basic tests or more advanced fuel testing depending on your fuel consumption volume, the specifics of your business, and the type of generator you possess. Simple DIY tests like visual inspection for water or sediment and odor assessment ought to be a part of routine fuel testing for every diesel generator. If there are any suspected fuel-related issues that you are unsure about, ask for a professional technician for help.  


Typically, diesel generator fuel testing methods include field tests, dipsticks, fuel analysis kit, hydrometers, laboratory tests, continuous monitoring systems and interpreting results. Once fuel issues are found, fuel polishing is an effective way to achieve optimal fuel quality. The process includes filtration, separation, and conditioning, which filters out the contaminants in fuel, separates and removes water from the fuel and conditions the fuel. This method is economical and environmentally safe. You don’t have to replace fuel and all fuel is recycled with no loss of product.


Do you still have any questions or problems about diesel generator fuel testing? Contact us today. Dingbo Power is a professional diesel generator manufacturer with over 17 years of experience in the power generator industry. We are solely focused on power generation and offer professional consultation to meet all your project needs. Though we don’t offer fuel maintenance process, our knowledgeable experts still can give you the right advice. Feel free to contact us with any questions, concerns, or inquiries to learn more about the products & services we provide.

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