Fuel Polishing: How It Really Works

Most Diesel Engine Failures
Originate In The Fuel Tank

Why Should Fuel Be Polished?

How Fuel Polishing Really Works

Globally, there are hundreds of millions of gallons of diesel fuel sitting in fuel storage tanks awaiting use. The demanding equipment can range from truck fleets to military bases.  Emergency power systems serving hospitals, police, fire, and other municipal services such as water and waste facilities, are key to keeping things working when the power goes out.  Some more invisible systems that are key to our daily life include hyper-scale data centers and cell phone towers, down to the rural farm or construction operation. The fuel being stored on-site is a critical asset that must be managed and maintained appropriately.

Through the logistical chain of fuel transportation and fuel storage, it is not uncommon for fuel to “pick up” contaminants along the way.

These fuel contaminants come in many forms including water, sludge, dirt, and other particulates that could jeopardize the integrity of the fuel or cause critical damage to the demanding engines that rely on the fuel as an energy source.

This could potentially cause downtime for mission critical facilities such as data centers and hospitals, or could leave fleet truckers stranded and ship captains “dead in the water”.

Fuel Contamination Inside Your Fuel Tank

Upper Left: Solid contaminants visible in a fuel sample. Foreground: Fuel contamination scraped from the bottom of a fuel storage tank

According to a study conducted by the Ponemon Institute, the average cost of a total data center outage was approximately $901,500.

The financial pitfalls of these potential vulnerabilities are a big reason why mission critical facilities are prioritizing fuel quality and maintenance, so that the backup power systems are reliable in the event of an unexpected power outage.

How Effective is Fuel Polishing?

Fuel polishing has become an important part of maintaining the operation of any facility or site that stores large quantities of fuel.

When power systems rely on an energy source, it is critical for that energy source to be of optimal quality for the demanding system(s). This is achieved through proper fuel management and fuel maintenance procedures.

Fuel polishing equipment must effectively remove various contaminants from the fuel, such as water, particulates and organic materials (sludge), as well as impact the fuel in some very special ways to prevent future problems from microbial or fungal growth in the futel. Fuel polishing systems often operate automatically on a programmed schedule and feature multiple phases of filtration and treatment of the fuel within them, the first phase being a fuel water separator.

The fuel filter / water separator, typically the first, or primary filtration step, features various stages of filtration where the water and large particulates are removed from the fuel with the use of centrifugal force and a filter element.

FPS FX Compact Series Installation

FPS FX Fuel Maintenance System marine installation on a Sabre Yacht

With water being heavier than the fuel in which it is suspended, the fuel water separator can successfully remove the majority of the water present in the fuel by spinning the fuel and the heavier particulates at a high velocity.

As an extra layer of filtration, the fuel filter / water separator also features a filter element to capture larger particulate (usually 10 microns and larger).

Once the fuel leaves the fuel water separator, most fuel maintenance systems feature a final or secondary stage of filtration that features a highly-efficient fine filter element. These elements can capture particulate as small as 3 microns in size in addition to absorbing any remaining water.

Fine filter elements are available in a wide range of micron sizes, and can be designed to capture water in addition to particulates if it’s deemed a water blocking element.

What can be perceived as redundancies, the strategic use of multiple filters can extend filter life, increase filtration efficiency and effectiveness, as well as prolong the lifetime of critical equipment within these polishing systems.

By continual removal of contaminants, fuel polishing systems can consistently ensure your fuel is of optimal quality thereby protecting the demanding equipment from premature onboard filter clogging, damage, and unexpected downtime.

Fuel Conditioner

Without a Fuel Conditioner, any system that only uses fuel / water separator technology and particulate filters is not a fuel polishing system as all it does is filter the fuel.

Key to Fuel Polishing is the impact needed on microbes and fungal contamination and the breakdown of the fuel itself caused by the agglomeration of the asphaltene component of your fuel that is evidenced by the fuel appearing dark brown or black and the accumulation of (what appears to be) a black tar substance on the bottom of your fuel tank.  To prevent future growth and the return of the floating organic debris in fuel and the returning of the fuel to the clear and bright condition that assures the optimal performance of the the fuel, you must use a Fuel Conditioner in your system.

The solution to suspected microbial growth and the results of asphaltene agglomeration in your fuel is the application of LG-X Series Fuel Conditioning Technology. Fuel Conditioners, when installed in a fuel re-circulation system or in-line in your equipment fuel system, will reverse the process of fuel breakdown, prevent microbial growth, restore fuel filterability, enhance combustibility, and prevent clogged filters and tank sludge. Optimizing fuel droplet size results in combustion efficiency, improved filterability and lower operating costs. (For a detailed explanation of how the LG-X Series Fuel Conditioner performs, see the web page “Learn More About Magnetic Fuel Conditioning”)

The LG-X Series Fuel Conditioner will also disperse and return to solution the asphaltene clusters the result in stored fuel degradation and return the fuel to a clear and bright appearance, a process sometimes referred to as “Fuel Polishing”. (For additional information, see “Diesel Fuel Polishing”)

Operating on the principal of induction on the process of combining kinetic and magnetic energy to influence the behavior of electrons, the AXI Fuel Conditioner provides a powerful magnetic field and the flow of fuel provides the kinetic energy. The process of how the LG-X Series Fuel Conditioner makes clear, bright and more combustible fuel as well as restoring degraded fuel and eliminating the effects of microbial contamination is compelling.

Fuel Conditioner Stops Ferris MetalAs the LG-X Series Fuel Conditioner does not filter the fuel, but treats it as it passes through the unit, there is seldom any reason to suspect that a restriction is in the LG-X Series Fuel Conditioner. However, there are situations where the benefit of circulating your fuel through a magnetic unit has added benefit. Should the LG-X Series Fuel Conditioner be used in a situation where a fuel tank itself is in poor condition, where the tank may be rusted on the inside and rust flakes may be coming loose, the LG-X Series Fuel Conditioner would prevent the sharp metal flakes from progressing to the fuel filter where they may pierce the filter medium and allow unfiltered fuel to proceed to the fuel system. Also, should the source of your fuel be questionable, such as a marine vessel that fuels at island fuel stops with little oversight, or remote mining operations where a supplier may not be reliable, having the LG-X Series Fuel Conditioner installed to stop metal shavings or other ferrous debris that may be the result of maintenance on upstream distribution equipment could be a great benefit.

Should a fuel restriction that cannot be traced to a clogged filter element make the LG-X Series Fuel Conditioner suspect, you can remove the face plate, remove the magnet and wipe it off with a shop rag and replace the magnet and face plate. An extreme example is pictured to the left. A spare parts kit for the LG-X Series Fuel Conditioner includes a new face panel O-Ring and replacement screws to fasten the face plate.

To completely reverse the buildup of particulates and fuel components that have attached themselves to the fuel tank bottom and sides, the fuel system lines, and inside surfaces of engine components, combine the use of the LG-X Series Fuel Conditioner with regular use of AFC Series Diesel and Gasoline Fuel Treatment and Tank Cleaning Additives. Unlike off-the-shelf additives that lubricate the fuel pump and limit their effectiveness to cleaning the injectors, the AFC Fuel Treatment and Tank Cleaning Additives reverse the long term buildup of sludge and degraded organic materials that have accumulated over time in the tank bottom, removes carbon buildup from engine components and stops the degradation of fuel injectors caused by the acids and degraded fuel components.

Biocides Do Not Solve the Contamination

Biocides are often sold/bought with the idea that it will solve all contamination issues rooted in microbial growth. Unfortunately, it is impossible to perfectly sterilize your fuel, meaning there will always be microbes waiting to re-propagate, especially with water still present within the tank.

Microbial growth, often mistaken as algae, is responsible for the development of a sludge-like byproduct that is usually responsible for the premature clogging of on-board engine filters.

The use of biocides to address microbial contamination presents a number of issues in its use.

First, through “killing” the microbes, you are left with the same levels of unwanted biomass within the fuel. Introducing biocides does nothing to remove the sludge or particulate present in the fuel.

Sludge in Fuel Filter

Excess sludge and microbial growth captured in a fuel filter

Second, using biocides doesn’t do anything to solve the root cause of rampant microbial growth: water.

These microbes thrive where the fuel and water layers meet, living in the water while consuming the hydrocarbons in the fuel. By removing water from the fuel, you are reducing the ability for the microbes to proliferate in the first place.

Biocides simply add more foreign non-petroleum contaminants to the tank, diluting your fuel further. This does nothing to remove the contaminants from your fuel.

The use of biocides may just cause you to clog filters more frequently, while not addressing the water that is in your fuel tank. After intital biocide treatment, this residual water source will allow new microbial growth, adding to the contamination problem that the biocides were originally intended to treat.

Where Does the Water in Fuel Come From?

Typically, condensation occurs within the fuel tank resulting in water droplets getting into the fuel. The more headspace (the space between the top of the fuel load and the top of the fuel tank) there is the more room for condensation to develop. In time, free water will accumulate as its own layer beneath the fuel.  As temperature changes outside the tank causes the fuel to warm and cool, expansion and contraction of the fuel with these temperature changes causes the tank to “breath” in and out, drawing moist air into the tank.  Condensation then causes water to accumulate as droplets move to the tank bottom over time.  Pollen, fungi and other microbial organisms are drawn into the tank with the air.  Use of filtered breathers that also captures and holds moisture with desiccant material prevents this migration of water into your tank at bay

Water can also be introduced into the fuel during transportation. After fuel is refined, it is often “passed through” multiple tanks and trailers before reaching its final destination. Many of these tanks hold potential to have accumulated condensation and water of their own.

This leaves multiple opportunities for the fuel load to be exposed to and contaminated with water that may have already been present in one of these tanks or trailers.

Logistically, it is tough for fuel providers to properly vet the fuel, creating a lapse in time between intended fuel quality and the actual fuel quality the consumers may receive.

This is why it is important for consumers to be vigilant regarding the quality and cleanliness of the fuel they receive.

How Do I Know I Need to Polish My Fuel?

There are a number of ways to determine if the fuel you have stored is in need of polishing. With fuel quality being so important to operational reliability, it should be a priority for maintaining the integrity of this critical energy source.

The most accurate way to know if your fuel is contaminated is to sample the fuel and get it tested for microbial growth and other forms of contamination.

Many testing labs can take more than a few days to receive, test, and report on the results of the tested fuel sample. There are alternatives to this method of testing, and FUELSTAT® instant fuel test kits are available to test fuel on-site and report results within fifteen minutes.

This testing method not only reports results quickly but eliminates the possibility of inaccurate results due to the time it may take for the samples to be tested.

When testing is not an immediate option to determine fuel quality, there are also ways to tell visually and operationally if the fuel quality isn’t where it needs to be.

If engine filter changes are becoming more frequent than usual, the buildup of fuel contamination can likely be the cause. If large amounts of thick sludge are found in your filters, it is likely that there is a much greater presence of sludge within the fuel tank.

When the equipment/engines that the fuel is supplying experiences rough idles, operational inconsistencies, or smoke, contaminated fuel may also be the culprit of these issues.

Side-by-Side Fuel Samples Before and After Fuel Polishing

Side-by-side fuel samples taken before and after fuel polishing

Visually, clean fuel will be yellow, orange, or red in hue (depending on fuel type and dye) and shouldn’t be extremely cloudy or difficult to see through. When fuel has been sitting for a prolonged period of time (6 months or longer), it is best practice to polish the fuel as stored fuel becomes more susceptible to degradation and contamination over long periods of time.

How Often Should I Polish My Fuel?

Fuel polishing cycles can vary between volume and conditions, but there are a few recommended best practices known to keep fuel within the desired fuel quality range.  Regions with higher humidity or where equipment is in close proximity to sea water or lakes require more frequent fuel polishing and with special attention to water removal.

There are two types of fuel polishing systems, mobile and automated.

Mobile fuel polishing systems are often mounted on a cart or trailer and are brought on-site to the fuel storage tank(s) periodically to polish the fuel. The portability of these systems allows one fuel polishing cart to service multiple tanks.

Polishing Trailer Operation

MTC Fuel Polishing Trailer being used to polish fuel within fuel storage tanks

If mobile systems are not used often enough, this could cause the fuel in the storage tanks to fall out of the desired fuel quality specification.

Depending how many fuel tanks are in need of polishing, a single mobile system may not be practical enough to keep all of the fuel within the desired fuel quality specification.

Automated fuel polishing systems are typically mounted near the fuel storage tank and have programmable features that allow for fuel polishing schedules to be determined and executed without human intervention.

STS System Installation

STS Enclosed Fuel Maintenance System installed on a outdoor fuel storage tank

This outshines mobile systems in that the fuel is routinely being cycled through the polishing system. In doing so, the fuel does not sit for long periods of time, preventing degradation and contamination.

What to Remember About Fuel Polishing

Biocides are not an effective alternative to fuel polishing when combating fuel contamination. Fuel polishing is critical to maintaining the operational integrity of your energy source.

Contaminated fuel can spell disaster in many applications, and by prioritizing fuel cleanliness you are increasing the overall reliability of your engine, equipment, site, or facility.

By creating a fuel maintenance procedure that includes fuel polishing, the stored fuel can last much longer than if it wasn’t being polished. Keeping the fuel free from harmful contaminants allows the fuel to be a long-term reliable energy source that is less likely to harm the equipment it is meant to supply.