The cloud point of No. 2 diesel is around 14 degrees Fahrenheit. Switching to a winter blend 15 degrees above cloud point is a decent rule of thumb.
What is meant by cloud point?
When oil is refrigerated to a low temperature, the cloud point is the temperature at which wax (paraffin) begins to separate, and it is an essential indicator of practical performance in low-temperature automotive applications.
What affects diesel cloud point?
The lower the pour point and cloud point temperatures become as the additive concentration in the additive-fuel mixture increases. Toluene, Xylene, n-Heptane, and Ethanol had the greatest to smallest effects on the cloud point of diesel fuel, according to the study.
What is cloud point and pour point?
is the temperature at which the first crystals begin to form. The pour point of a liquid is the lowest temperature at which it loses its flow characteristics. The temperature is reduced in 3°C steps until a cloud, haze, or wax crystal forms at the bottom of the test tube in a freezer that can chill below 0°C. The cloud point is the temperature at which a cloud forms. After reaching the cloud point, the temperature is gradually decreased by 1°C until the fuel loses its flow characteristics or stops moving. When utilized in cold climates, the cloud and pour point properties of the fuel are important.
What is a cloud point test?
A variety of tests are available to determine the low-temperature qualities of diesel fuels and their impact on vehicle low-temperature operability. Cloud Point is the most conservative indicator of a fuel’s low-temperature operability. It’s also a good indication of a fuel’s low-temperature operability limit if it doesn’t have any operability additives. Under the test conditions, the cloud point is defined as the temperature at which a cloud or haze of wax crystals begins to develop in the fuel. These crystals can build up in filters, causing the fuel system to get clogged. Cloud point is usually unaffected by fuel additives that increase low-temperature operability. These additives are used in diesel fuel to prevent agglomeration or to change crystals in other ways so that filter clogging is minimized.
For performing this test, a variety of manual and automatic options have been devised.
The manual approach is the most widely used cloud point test (ASTM D2500). In this test, free moisture is removed from a sample by heating it to at least 14°C above the predicted cloud point. The sample is then poured into a test jar, which is sealed with a cork and has a thermometer on the bottom that measures the sample temperature.
By placing the sample jar into a jacket that had previously been placed into the cooling bath to chill, the sample is cooled in a cooling bath maintained at a consistent temperature (Figure 1). The chilling bath does not immediately contact the sample jar. A felt or cork disk on the bottom of the jacket and a gasket around the outside of the sample jar keep an air gap of roughly 5.5 mm between the outside of the sample jar and the interior of the jacket.
A series of chilling baths may be necessary, depending on the initial sample temperature and the predicted cloud point. Each bath is kept at a lower temperature than the one before it. This gives you some control over how quickly the sample cools. This test’s cooling rate is not defined, and therefore does not remain consistent during the test. ASTM D2500 cooling rates are typically on the order of 1°C/min. Table 1 lists the bath temperature requirements, and Figure 2 shows how a typical sample temperature changes during the duration of the test.
What is the cloud point of winter diesel?
The cloud point of No. 2 diesel is around 14 degrees Fahrenheit. Switching to a winter blend 15 degrees above cloud point is a decent rule of thumb. It’s time to blend in No. 1 when overnight temps drop below 30 degrees F.
How is cloud point calculated?
An alternative to the manual test process is ASTM D5773, Standard Test Method of Cloud Point of Petroleum Products (Constant Cooling Rate Method). It has been determined to be equivalent to test method D2500 when using automatic apparatus.
The D5773 test technique finds the cloud point in less time than the manual D2500 approach. Using this automated procedure, less operator time is required to complete the test. There is also no need for an external chiller bath or refrigeration equipment. Within a temperature range of -60 °C to +49 °C, D5773 can determine cloud point. Temperature resolution of 0.1 °C is used to report the results.
The test sample is cooled at a consistent rate of 1.5 +/- 0.1 °C/min by a Peltier device in accordance with ASTM D5773. The sample is constantly illuminated by a light source during this time. The sample is continuously monitored by an array of optical detectors for the initial emergence of a cloud of wax crystals. The cloud point is determined as the temperature at which wax crystals emerge for the first time in the sample.
Can diesel fuel freeze?
When temperatures drop, the bonds between diesel fuel molecules become more rigid, causing them to connect more tightly. The procedure is repeated until thin sheets of diesel are linked together, resulting in a waxy material in the fuel. A little cloudy appearance within the fluid may be the first sign. **
Enough of these wax pieces accumulate in fuel filters over time, clogging them and preventing fuel flow. If the process continues, the fuel may entirely gel, forming a waxy goo that is semi-solid. The fuel supply to the engine has been cut off, and the vehicle is unable to run!
In frigid conditions, the term “gelled” is used to describe unusable equipment. The wax creation process is aided by frozen water molecules in diesel fuel, which provide a template for the wax to develop on. Biodiesel blends tend to hold more water in suspension than other fuels, exacerbating the problem.
What’s the difference between number 1 and number 2 diesel?
The fundamental difference between Diesel #1 and Diesel #2 is the cetane rating, which, like the octane of gasoline, indicates igniting ease. It’s all about fuel efficiency, volatility, and seasonality, really.
Less wear on your engines’ batteries implies a faster and more efficient start. The increased cetane grade also helps diesel engines run more smoothly by lowering maintenance requirements.
The additional lubricants in Premium Diesel assist keep fuel system parts moving easily. The fuel pump’s and other fuel system components’ lives are extended as a result of the reduced friction.
Fuel systems can become clogged with sediments and other particles over time. While the engine is operating, detergents are injected to Diesel #1 to clean injectors and other fuel system components. Not only does a clean fuel system last longer, but it also enhances fuel efficiency and horsepower production.
Diesel #1 contains lubricants and detergents, as well as other fuel additives that improve engine performance and save downtime. Even in a well-sealed fuel system, air moisture can find its way in and cause major engine problems. Demulsifiers in premium Diesel work to separate emulsified water from the fuel so that it can be filtered out; even in a well-sealed fuel system, air moisture can find its way in and cause major engine problems. Corrosion inhibitors keep rust and corrosion at bay, while stabilizers keep blockages and buildup at bay.
Diesel #1 is sometimes known as winter diesel since it operates better in colder conditions than Diesel #2. It has a lower viscosity and does not gel when exposed to cold temperatures. Most stations sell a premium Diesel blend that is tailored to the local climate.
While premium diesel has a number of advantages, such as fewer maintenance and equipment downtime, regular diesel is less expensive at the pump, which is an essential consideration. However, total cost of ownership should take into account not only the cost savings from the fuel, but also the impact on ongoing maintenance costs. The age and size of your fleet may play a role in deciding between Diesel #1 and Diesel #2.
When deciding between Diesel #1 and Diesel #2 for your fleet, keep in mind that premium Diesel quality differs from station to station. If you choose Diesel #1, make sure your drivers get their fuel at reliable high-volume stations.
Do you want to learn more about the effects of diesel choices on fuel systems? To talk with an equipment professional, contact your nearest Papé Kenworth office now.
What type of diesel should I use in the winter?
Winterized diesel fuel is a blend of #1 and #2 fuels that contains a higher proportion of #1 grade diesel fuel when blended together. During the months when it is too cold to use #2 grade, these fuels are employed.
The chemical mix including both grades of fuel should have adequate energy components and lubricating characteristics to prevent the chemical mix from gelling in cooler temperatures. The fuel economy typically decreases significantly during the winter months due to lower demand than during other times of the year.
In the winter, using #1 grade diesel fuel should never be a cause for concern. Long-term use in engines designed exclusively for #2 grade, on the other hand, may shorten the engine’s life cycle. Fuels of grades #1 and #2 can be blended at the same time. This means you won’t be inconvenienced if #1 grade is only available in the winter.
What is pour point of fuel?
The pour point of diesel fuel is an important quality criterion. It is a measurement of a fuel’s tendency to become more viscous and impede flowing when cold.
The pour point of a fuel is defined as 5 degrees Fahrenheit above the temperature at which it stops flowing due to the development of wax crystals that increase viscosity.
The pour point specification is the greatest temperature that can be tolerated. It is preferable to use a material with a lower pour point.
In general, lighter (lower boiling point) materials have a lower (better) pour point.