06/11/2025 | Press release | Archived content
If you store fuel on site, whether in bulk storage tanks or large generators or other stationary settings, then a reliable fuel supply plan is critical. Over time, stored diesel can degrade due to water contamination, sediment buildup, and microbial growth, all of which can lead to engine failure and costly downtime. Implementing a comprehensive fuel maintenance program-including regular fuel polishing-is important to ensure fuel quality and system reliability.
A clean tank means clean fuel you can count on. That's why consistent fuel sampling and regular fuel polishing are key to preventing disruptions and keeping your operations running smoothly.
What is Fuel Polishing?
Fuel polishing is a specialized multi-stage filtration process created to remove contaminants from stored fuel. Unlike standard fuel filtering, which happens at the point of use, fuel polishing is a proactive maintenance procedure that cleans the fuel within storage tanks, ensuring it remains in optimal condition for extended periods. It's the most effective process for maintaining an optimal tank environment.
The fuel polishing process involves several steps. First, 48 hours prior to the polishing, the tank is filled to its maximum capacity, and a shock treatment of biocide is applied. This kills all microbial growth in the fuel and along the tank walls and floor.
There are various policies that companies may follow when polishing a tank. Typically, these will include sweeping the bottom of the tank to remove loose sediment and water that has fallen to the bottom of the tank. Next, the remaining fuel will be pulled out of the fuel tank and run through progressively more advanced filtration to remove debris. Water separators are used to remove water from the fuel. Debris and oily water will be removed and disposed of following proper hazmat disposal methods.
Depending on the type of polishing needed, the polisher may circulate the fuel through the filtration several times, or fully remove all fuel from the tank and store it after it is filtered. This second method allows the inside of the fuel tank to be thoroughly cleaned, which is a separate process from the polishing. Finally, with the tank either swept or pressure cleaned and the fuel adequately filtered, the fuel will be replaced in the tank. Typically, lines will be flushed and filters replaced to put the tank in pristine condition.
By addressing these contaminants, fuel polishing helps maintain fuel quality, ensuring reliable performance of your equipment.
Can Fuel Polishing Be Done for Diesel and Gasoline?
Yes, fuel polishings can be done both for diesel and for gasoline. For diesel tanks, fuel polishing is targeted at removing microbial growth, sludge, and water. For gasoline, polishings are usually done to remove water, particularly in incidents where tanks are subjected to excess amounts of water.
The Importance of Regular Fuel Maintenance
Mansfield recommends fuel polishing annually or bi-annually to prevent buildup, slow degradation, and remove contaminants effectively. Regular maintenance not only extends the life of the fuel but also protects equipment from potential damage caused by poor fuel quality. This is where a fuel maintenance program becomes a necessary part of your operations.
Regular fuel testing and sampling-typically recommended two times per year in the spring and fall-can indicate whether fuel polishing is needed. Knowing the quality of your fuel starts with proper maintenance. Without routine testing and care, fuel quality can quickly deteriorate-you can't manage what you don't measure. A structured maintenance plan provides the peace of mind that both your tank and fuel supply remain clean, reliable, and ready when needed. Clean fuel doesn't stay clean by chance. Consistent sampling and testing are the backbone of maintaining fuel integrity, directly influencing the performance and reliability of your operations.
Signs Your Fuel May Need Polishing
"Water is one of fuel's worst enemies, often building up in your tank without you even realizing it", says Christine Russell, FS&S Project & Fuel Quality Specialist at Mansfield. Here are some signs that it's time for your fuel to be polished.
Indicators include:
If any of these signs are present, it's advised to conduct fuel testing and consider polishing to restore fuel quality.
Partnering with Fuel Maintenance Experts
Entrusting your fuel maintenance to an experienced team ensures your fuel supply stays reliable. Mansfield provides a full range of services-including fuel testing, fuel polishing, and customized additive treatments-tailored to meet the unique needs of your operation. With deep industry expertise and nationwide support, we offer solutions that maintain peak fuel quality, giving you confidence that your backup systems will perform when it matters most.
Proactive fuel maintenance-especially regular polishing-preserves the longevity and reliability of your engines. By addressing contamination before it causes equipment failure, you can ensure seamless, uninterrupted operations during the most challenging situations.