Diesel fuel is an essential component for many vehicles, equipment, and machinery, particularly in colder climates. However, one of the challenges associated with using diesel in low temperatures is the phenomenon known as “gelation.” When diesel fuel begins to gel, it can cause blockages, engine failure, and difficulty in starting up vehicles. Understanding when and why diesel starts to gel, along with how to manage it, is crucial for those who depend on diesel-powered engines in colder environments.
In this article, we will explore in detail the conditions under which diesel begins to gel, the factors influencing gelation, and how to prevent this issue from affecting your vehicle or machinery.
What is Diesel Gelation?
Diesel gelation refers to the process where diesel fuel thickens and becomes gelatinous due to low temperatures. This happens when the paraffin waxes present in diesel fuel begin to solidify and clump together, forming a gel-like substance. When diesel gels, it can clog filters, injectors, and fuel lines, making it difficult for the engine to run properly.
How Low Does Temperature Have to Be for Diesel to Gel?
The temperature at which diesel fuel begins to gel can vary depending on several factors, including the specific blend of diesel, its additives, and the presence of waxes. Generally, diesel fuel will start to gel at temperatures around 15°F to 20°F (-9°C to -6°C), although this range can fluctuate.
Diesel Fuel and Paraffin Waxes
Diesel contains paraffin hydrocarbons, which are waxy substances that remain in liquid form at higher temperatures but begin to crystallize and solidify as the temperature drops. As the temperature continues to fall, the wax crystals bind together, forming a gel. This is why cold weather can be particularly problematic for diesel engines, as the fuel’s viscosity increases, restricting its flow.
Types of Diesel Fuel and Their Gelation Points
Different types of diesel fuel have different gelation points:
Regular Diesel (No Additives) – Regular diesel fuel, such as No. 2 diesel, has a gelation point of around 15°F to 20°F (-9°C to -6°C). This fuel is commonly used for everyday transportation, but it may not perform well in extreme cold without proper additives.
Winterized Diesel – In regions where cold temperatures are common, diesel fuel is often “winterized” by blending No. 1 diesel or adding anti-gelling agents. This reduces the gelation point to somewhere around -10°F to -20°F (-23°C to -29°C), depending on the specific formulation.
Biodiesel – Biodiesel, which is derived from organic materials, can gel at higher temperatures than regular diesel. It can start to gel as high as 30°F (-1°C), making it more susceptible to cold weather issues.
Factors Affecting When Diesel Starts to Gel
While temperature is the primary factor, other elements can influence the gelation process:
1. The Type of Diesel
As mentioned earlier, the specific type of diesel fuel plays a significant role. Diesel fuel with a higher paraffin content will gel at higher temperatures. On the other hand, fuels that have been treated with additives or blended with lower-wax diesel will gel at lower temperatures.
2. Additives in Diesel
Many modern diesel fuels are treated with additives to help improve performance in colder climates. These additives may include:
Anti-gelling agents – These prevent or delay the solidification of wax particles in the diesel.
Cold flow improvers – These additives work by altering the structure of the wax particles, reducing the point at which they clump together.
De-icers – These are often used to prevent the formation of ice crystals that can form in the water present in diesel fuel.
The more effective these additives are, the later the gelation process will begin, even in colder temperatures.
3. The Diesel’s Cloud Point
The cloud point of diesel is the temperature at which paraffin crystals first begin to form. This is an early sign that the diesel is beginning to gel. Diesel with a higher cloud point will start to form crystals at higher temperatures, making it more prone to gelling.
4. Contamination with Water
Water contamination in diesel can lower the gelation point. Water droplets can freeze inside the fuel, creating solid blocks that can cause fuel lines to clog and fuel filters to become blocked. Additionally, when water mixes with diesel fuel, it can accelerate the crystallization of waxes, contributing to gelation.
5. Storage and Handling
The way diesel fuel is stored and handled can also influence its susceptibility to gelling. If diesel is stored in tanks or containers that are not properly insulated, it may freeze or gel more easily in cold weather. Similarly, if fuel is stored in areas with significant temperature fluctuations, it can increase the likelihood of gelation.
What Happens When Diesel Starts to Gel?
When diesel begins to gel, several issues can occur:
Clogging of Fuel Filters – As wax crystals form, they can clog fuel filters, preventing the fuel from reaching the engine.
Reduced Fuel Flow – The gelled diesel becomes thicker, making it difficult for the fuel to flow through the fuel lines, causing the engine to sputter or fail to start.
Damage to Engine Components – If gelled fuel is allowed to circulate, it can cause wear and tear on the fuel system components such as injectors and pumps.
Starting Problems – Diesel engines rely on smooth fuel flow to start properly. When diesel gels, the engine may fail to start, or it may take much longer to turn over.
Preventing Diesel Gelation
To ensure that your diesel engine runs smoothly during colder weather, there are several strategies you can implement to prevent diesel from gelling.
1. Use Winterized Diesel Fuel
One of the simplest ways to prevent gelation is to use winterized diesel. Winterized diesel is specifically blended to reduce the risk of gelling, with additives that lower the cloud point and gel point of the fuel. Ensure that you are using the correct grade of diesel fuel for your local climate conditions. If you’re in an area where temperatures regularly fall below freezing, it’s especially important to switch to winterized diesel.
2. Add Anti-Gelling Additives
If winterized diesel is not available, you can add anti-gelling additives to your regular diesel fuel. These additives prevent the paraffin wax in the fuel from crystallizing, even in lower temperatures. They can be added directly to the fuel tank, and they are especially useful for short-term cold weather protection.
3. Store Diesel Fuel Properly
Proper storage of diesel fuel is critical in preventing gelation. Ensure that your storage tank is insulated to maintain a more consistent temperature. This is especially important for outdoor storage where temperature fluctuations can cause problems. Additionally, regular cleaning of the storage tank is essential to remove water and other contaminants that could contribute to gelation.
4. Keep Your Vehicle or Equipment Inside
If possible, store your diesel-powered vehicle or equipment in a heated garage or facility to protect it from extreme cold. This can prevent the fuel in the tank from reaching temperatures low enough to gel.
5. Use Fuel Line Heaters
Fuel line heaters are devices that can be installed to keep the fuel warm as it flows through the fuel lines. These heaters are especially helpful in extreme cold weather, ensuring that the diesel fuel doesn’t reach the temperature where gelation could occur.
Conclusion
Diesel fuel typically begins to gel at temperatures between 15°F to 20°F (-9°C to -6°C), depending on the specific type of diesel and its additives. The process is influenced by several factors, including the fuel’s paraffin content, additives, and the presence of water. By understanding when diesel begins to gel and taking preventative measures such as using winterized diesel, adding anti-gelling additives, and ensuring proper storage, you can keep your diesel engine running smoothly even in the coldest conditions.
Related Topics:
- Will Gelled Diesel Fuel Thaw?
- Where Is Diesel Fuel Refined?
- Can You Run an Oil Boiler on Red Diesel?