Water enters diesel in three primary forms:

• Dissolved (invisible, fully in solution within the fuel).
• Emulsified (tiny suspended droplets that make the fuel appear cloudy or hazy).
• Free (separate liquid layer that settles at the tank bottom, since water is denser than diesel).

Main Sources of Water Contamination

Human Error or Poor Handling Practices Simple oversights like leaving fill caps unsecured, exposing drums or portable tanks to rain, improper storage, or careless refueling can allow direct water entry.

Condensation (by far the most common source) Temperature fluctuations cause fuel tanks to “breathe.” As the fuel and tank cool (e.g., overnight, during seasonal changes, or in varying weather), warm, humid air is drawn in through vents, breathers, or fill pipes. This air cools upon contact with the colder tank walls or fuel surface, reaching its dew point and condensing into liquid water droplets. These droplets accumulate and mix into the fuel. This process is exacerbated in:

Above-ground tanks (greater temperature swings).

Partially filled tanks (larger air space and surface area).

Humid climates or environments with high day-night temperature variations.

Contaminated Fuel from the Supply Chain or Delivery Water can already be present when you receive the fuel. Causes include:

Insufficient settling time at the refinery or during transport.

Shared pipelines or transport systems that introduce moisture.

Contaminated supplier storage tanks. Excess dissolved water may exceed saturation (especially as fuel cools), causing it to “fall out” as free water that settles in your tank.

Leaks or Compromised Tank Integrity External water enters through:

Damaged seals, cracked tanks, faulty vents, loose fill caps, or degraded spill containment.

Rain, snow, pressure washing, groundwater seepage, flooding, or even accidental drainage of collected rainwater into the tank.

Need help? See https://dieselcraft.com/portable-fuel-polishing/

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When biodiesel is poorly made—often referred to as “bad biodiesel”—one of the biggest red flags is a high concentration of glycerine (or glycerin/glycerol). Here’s why that matters:
What Glycerine Is in Biodiesel
• Glycerine is a byproduct of the transesterification process used to make biodiesel from fats or oils.
• Ideally, it should be separated and removed during production.
• If not properly removed, it remains in the fuel as free glycerine or bound glycerides (mono-, di-, or triglycerides).
Why High Glycerine Is a Problem
• Engine Damage: Excess glycerine can clog fuel injectors, form deposits on pistons and valves, and lead to poor combustion.
• Cold Weather Issues: Glycerine solidifies at relatively high temperatures, which can cause fuel gelling and blockages in cold climates.
• Storage Instability: Glycerine can separate out over time, reducing shelf life and causing sediment in tanks.
• Fails Standards: High glycerine levels mean the fuel doesn’t meet ASTM D6751 or EN 14214 standards, making it unsuitable for commercial use.
How It’s Measured
• Standards like ASTM D6584 and EN 14105 use gas chromatography to measure both free and total glycerine in biodiesel.
• Acceptable limits are very low—typically <0.02% for free glycerine and <0.24% for total glycerine in B100 biodiesel.
Can It Be Fixed?
• Yes, but it requires reprocessing or purification, such as:
• Washing the biodiesel to remove impurities
• Vacuum distillation
• Membrane filtration or electrodialysis for crude glycerine recovery
Contact www.dieselcraft.com for a fuel purifier and centrifuge to fix the problem.

MORE INFO

The post Black or Brown Solids in My Diesel Fuel: Causes and Solutions appeared first on Dieselcraft.

The Importance of Fuel Maintenance

The fuel that powers these emergency generators is just as crucial as the generators themselves. Over time, fuel can degrade due to microbial contamination, water accumulation, sediment buildup, and natural aging. If left unchecked, this deterioration can lead to generator failure when it is needed most.

Poor fuel maintenance can cause clogged filters, damaged injectors, corroded fuel systems, and reduced generator performance. In the worst-case scenario, fuel contamination may result in complete generator failure during a critical emergency.

Advantages of Fixed Fuel Polishing Systems

To counter these risks, many hospitals have adopted fixed fuel polishing systems. These systems clean and filter stored fuel, removing contaminants and water to maintain its integrity. The benefits of fuel polishing systems include:

1. Enhanced Reliability: Ensures fuel remains in optimal condition, reducing the risk of generator failure.
2. Extended Equipment Lifespan: Prevents damage caused by degraded fuel, prolonging the life of both the fuel and the generator.
3. Cost Efficiency: Reduces maintenance expenses, prevents costly generator repairs, and extends fuel usability.
4. Regulatory Compliance: Helps hospitals meet fuel maintenance regulations, avoiding potential penalties and ensuring operational readiness.

Risks of Ignoring Fuel Maintenance

Neglecting fuel care can lead to significant consequences, including:

1. Unreliable Backup Power: Degraded fuel increases the risk of generator malfunction or total failure.
2. Higher Operational Costs: Poor fuel management results in expensive repairs, equipment replacement, and potential fines for non-compliance.
3. Patient Safety Hazards: A power failure in a hospital can have life-threatening consequences if essential medical equipment becomes inoperable.

Ensuring Reliable Emergency Power

Proper fuel management requires routine testing, monitoring, and maintenance to ensure high fuel quality and availability. Hospitals must implement robust fuel management protocols to safeguard their critical infrastructure, minimize financial risks, and, most importantly, protect patient lives. In times of crisis, having a well-maintained fuel system can make the difference between seamless medical care and a catastrophic power failure. MORE INFO

The post The Vital Role of Generator Fuel in Hospitals appeared first on Dieselcraft.

Here are the key questions to investigate:

• Is the fuel clear and bright or cloudy?
• Are you using an additive? If so, which one, at what ratio, and how often?
• Is the entire fuel volume cloudy, or only the bottom around the fuel pick-up?

Fuel Sampling Steps

1. Take a sample from the water separator. Is the fuel clear and bright, or cloudy?
2. Take a sample from the top of the fuel tank. Is it clear and bright, or cloudy?
3. Take a sample from the next fuel delivery. Is it clear and bright, or cloudy?

Checking for Overdosing Issues

• Is your supplier providing a winter blend fuel?
• Is the supplier blending the additive? If so, ask for the exact ratio.
• If the fuel supplier overdosed the fuel—or if you added a cold flow improver to an already treated winter blend—you may have caused the issue.
• Water reacts to excessive additives, preventing it from being trapped by a water-blocking filter.

Understanding Additive Ratios

It’s crucial to use the correct amount of additive:

• There are 128 ounces in 1 gallon.
• If an additive treats 1 gallon per 1,000 gallons of fuel, then 1 ounce treats 7.8 gallons.
• Did you add more than the recommended amount? More is not better!

Locating and Removing the Problem Fuel

• Overdosed additives tend to sink to the tank bottom, where the engine’s fuel pick-up is located.
• Take samples from different points in the tank to determine where clear and bright fuel transitions to cloudy.
• Pump off and store the bottom fuel until the water naturally separates over time.

Testing for Contamination

To test fuel clarity, use this method: Diesel Fuel Contamination Test.
If the results are inconclusive, a lab test ($200–$400) may be required—contact us for recommendations.

Conclusion

Diesel fuel additives are a cost-effective way to improve engine performance in cold weather. They enhance cold flow without sacrificing power or performance and don’t reduce lubricity or cetane levels like kerosene.

However, excessive additive use can cause contamination issues. Based on our findings, the fuel was likely delivered with too much winter blend additive or was overdosed during treatment.

The post Troubleshooting Fuel Contamination Issues appeared first on Dieselcraft.

Dirty Fuel Might Be the Culprit!

Get your engines running at peak performance with Dieselcraft Fuel Polishing Machines! Our cutting-edge machines expertly eliminate water, sludge, and contaminants from your fuel, ensuring your diesel is always clean and ready for action. Whether you’re powering boats, trucks, or backup generators, Dieselcraft guarantees your fuel stays in prime condition—helping you save precious time, slash maintenance costs, and reduce fuel waste!

Boost Fuel Efficiency
Protect Your Engine’s Longevity
Lower Maintenance Costs

• Intuitive and High-Quality Design
• Perfect for Emergency Power Systems
• Proven Results in Eliminating Fuel Contamination

Don’t let dirty fuel compromise your performance. Choose Dieselcraft for reliable fuel solutions!
Learn more today! https://dieselcraft.com/portable-fuel-polishing/

The post Is Your Backup Generator Struggling Due to Diesel Engine Performance Issues? appeared first on Dieselcraft.

A lot of people wee fooled for a long time.

Relatively clear fuel but clogged filters after 2,000 mile in a Class 8 Truck.

The problem was constant filter clogging with a black colored material.

Generally if it is a fuel tank with a black film clogging filters we assume it is bacteria so we recommend a tank cleaning additive.

They used an additive, but the problem did not go away.

We asked for photos.

Clear fuel but filters were clogged with the mystery black material.

The filter and fuel sample were sent to a lab for answers. No bacteria was found.

We again gave our best guess, could it be rubber. Some fuel blends with high amounts of biodiesel are not so friendly with some rubber hoses. The fuel eats up the hose from the inside out and causes a similar black substance that plugs filters.

Again back we go to the lab to identify the culprit.

The tank was drained, washed and this residue was found. It was send to a lab for identification.

No it’s not rubber it is soot from the engine. The engine has 5 of 6 bad fuel injector seals and this was sending engine soot back down the return line to the fuel tank. So as we cleaned the fuel and the tanks, the engine was creating the problem as the engine was running.

To self test filter plugging mysteries take a sample of the sludge and mix it with as small amount of Xylene.

Xylene is as synthetic paint thinner available at the hardware store. This should dissolve any biomass sludge if the problem is bacteria. If it does not, rinse in warm soapy water and rub the material between your fingers. Feel gritty? Could be soot or does it feel like rubber?

BUY HERE

Have less than 100 gallons of fuel and need a quick and simple way to get the water and large solids out?

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The post Clogged Fuel Filters? Here’s Why They Don’t Solve the Problem appeared first on Dieselcraft.

Water Contamination
Even small amounts of water in diesel can crack injectors, corrode fuel lines, and reduce combustion efficiency. Sources include biodiesel blends, condensation, rain, and poorly maintained storage tanks.

Microbial Growth and Sludge
Bacteria in fuel (“fuel bugs”) produce bio-mass sludge that clogs filters and reduces engine performance. Mislabeling this as “algae” is a common error.

Fuel Degradation
Diesel begins breaking down within 30 days of refining, forming dark deposits that foul systems and shorten engine life.

Solutions: Prevention and Treatment

• Fuel additives: Improve combustion, lubricity, cold flow, and cetane rating
• Water removal: Drain tanks, use separators
• Fuel polishing: Circulate and filter fuel regularly to remove contaminants
• Testing: Identify water or microbial contamination early using fuel test kits

Conclusion
Up to 80% of diesel engine failures are linked to poor fuel quality. Regular testing, proper storage, and treatment with additives and fuel polishing are the best ways to protect your engine, extend component life, and prevent costly downtime. BUY HERE

The post Diesel Fuel Quality: Prevent Engine Damage from Water & Contamination appeared first on Dieselcraft.