Fuel Polishing: 6 Things You Need To Know

Like so many good things, diesel fuel doesn’t last forever. But fuel polishing, also called fuel scrubbing, can make it last a lot longer.

Diesel fuel does not last forever.

You may not realize it, but diesel fuel has a shelf life. Over time, when left unused, it can grow stale and even turn bad. Fuel goes bad in equipment such as emergency generators that utilize fuel, but only infrequently, as needed.

It occurs when water molecules from tank condensation bond with the diesel fuel, providing food for microbial growth, but it can also happen when sludge, rust, and other solid impurities contaminate the fuel.

Most of the time, when fuel turns bad, you can easily tell. It may appear discolored when it gathers in the bowl below the filter, appearing yellow instead of cranberry. The fuel may also have an off smell, sometimes of varnish. A lab test can give you a conclusive assessment.

Luckily, you do not have to go through the costly process of disposing of and replacing old fuel when fuel polishing can renew your diesel. Regular fuel polishing is a key part of preventative maintenance. Polishing fuel occurs when the diesel gets run through a filter designed to capture water and other unwanted substances. It can prevent clogging of filters and damage to other components while preventing the need to dispose of fuel outright, which wastes the money spent on it. Some recommend having fuel polished every three years, while others say that more sedentary machines should undergo the process every six months.

Why is Diesel Fuel Polishing important?

Because left unused, diesel generator fuel can go bad. And if your fuel goes bad, you’ll have not one but two new problems:

• First, you’ll have to pay for unnecessary new fuel.
• Second, you’ll risk getting stuck in a blackout with no power. Generators need clean fuel to run reliably, and bad fuel compromises their functioning.

Diesel fuel polishing prevents such issues.

Fuel polishing achieves this by capturing water, microbes, rust, and sludge in the filter system. Without this process, such impurities often clog filters and damage other components, such as injectors and fuel pumps.

The result? We’ve been called out to several companies who ended up with engine failure or their generator suddenly stopping in the middle of a blackout…all due to bad fuel.

In some cases, injector repairs and a good diesel fuel polishing cleared everything out. But in the worst cases, this wasn’t enough; the company had to pay for an emergency repair visit, costly hazardous material disposal, and new fuel.

That’s why regular fuel polishing is a key part of preventative maintenance.

Since it’s an essential part of generator maintenance, we’ve collected common questions from customers and are answering them in both video and text below:

What is Fuel Polishing?

It’s the process of cleaning generator fuel. This process draws the fuel from the generator tank, through a filter system, and back into the tank. This filter system constantly circulates the fuel through the filter to purify it from common contaminants such as water, bacteria, sludge, and rust.

Since fuel that stands still for a long time is more vulnerable to microbial build-up, polishing is especially important for infrequently used equipment (i.e. most commercial generators).

Is Diesel Fuel Polishing Different from Fuel Scrubbing?

Short answer – no! Long answer – fuel scrubbing is another way to describe fuel polishing. These terms are interchangeable.

What’s the Difference Between Fuel Replacement and Fuel Polishing?

One saves you a lot of money, the other…does the opposite.

Diesel fuel polishing purifies your current fuel so that you can use it for a long time to come.

Fuel replacement means that you not only have to buy brand-new generator fuel, but also dispose of your current fuel. This is not only unnecessary (if your fuel can still be polished) but also expensive: since fuel is a hazardous material, the cost of its disposal is unpleasantly high.

Thus, fuel should only be replaced in extreme cases, when the fuel is too contaminated for even polishing to help. Regular fuel polishing will prevent such cases (and expenses).

How Often Does My Generator Need Fuel Scrubbing?

At least once every three years. In addition, run a fuel test every year. This will alert you to the need for polishing before more expensive problems arise.

How Can I Do Fuel Scrubbing Myself?

Fortunately, polishing fuel is not difficult! But it does require that you follow a step-by-step process. Watch the following video to see one of our generator technicians explain the whole process:

Cleaning a Generator’s Diesel Fuel Tank

It’s not difficult, and can save you money.

Polishing fuel is not difficult, but it does require that you follow a step-by-step process. Watch the video above to see the entire process and how it’s performed. Preventative maintenance, including fuel polishing, pales in comparison to a generator repair or its unavailability in case of an emergency.

Can I Schedule a Professional Generator Fuel Polishing?

Certainly! Call The Generator Experts at Duthie Power by calling 1-800-899-3931 or requesting a quote online here. Find out more about this and other important generator maintenance service.