About diesel fuel
Vendor Fuel Source and Quality: ASTM Diesel Standards, ISO cleanliness code; and what you need to know about today’s diesel fuel.
Where do Pacific NW vendors get their fuel?
Through its Pacific Operations unit, Kinder Morgan operates approximately 3,000 miles of refined products pipeline that serves Arizona, California, Nevada, New Mexico, Oregon, Washington and Texas. With roots dating back to 1956, it is the largest products pipeline in the Western U.S., transporting more than one million barrels per day of gasoline, jet fuel and diesel fuel to our customers. Additionally, the company-owned terminals provide services such as liquid petroleum product storage and loading facilities for delivery trucks.
In the United States, diesel fuel is controlled according the American Society for Testing and Materials Standard D975-97. This standard describes a limited number of properties that diesel fuels must meet. It should be noted that the requirements are all performance- based. They do not mandate the composition of the fuel, only the specific performance related requirements demanded of a fuel for a diesel engine. The requirements of D975 are described below.
Diesel fuel is characterized in the United States by the ASTM standard D 975. This standard identifies five grades of diesel fuel, we are only going to talk about the two most popular commercially diesel fuel used. No 1 and No. 2 diesel.
Grade No. 1-D and Ultra Low Sulfur 1-D: A light distillate fuel for applications requiring a higher volatility fuel for rapidly fluctuating loads and speeds as in light trucks and buses. The specification for this grade of diesel fuel overlaps with kerosene and jet fuel and all three are commonly produced from the same base stock. One major use for No. 1-D diesel fuel is to blend with No. 2-D during winter to provide improved cold flow properties. Ultra Ultra Low sulfur fuel is required for on-highway use with sulfur level < 0.05%.
Grade No. 2-D and Ultra Low Sulfur 2-D: A middle or mid-grade distillate fuel for applications that do not require a high volatility fuel. Typical applications are high-speed engines that operate for sustained periods at high load. Ultra Low sulfur fuel is required for on-highway use with sulfur level < 0.05%.
Dirty fuel will cause premature parts failure in equipment of any age. Today’s new and improved Tier 4 rail injector engines are more efficient, they burn cleaner, and run better, they are more powerful than ever before. But there are things that make fuel quality more important than ever. Because of the extremely high pressures (upwards of 35,000psi at the injector tip), the possibility of damage from dirty wet fuel is more prevalent than ever, this damage is much more pronounced in newer equipment with HPCR (High Pressure Common Rail) fuel systems. Hard particulate is commonly referred to as “dirt”, but is in fact made up of a wide variety of materials found at job sites (coal, iron, salt, etc.), generated by fuel tanks and lines (rust, corrosion, etc.) and inside engines (carbonatious materials and wear particles).
Frequent diesel fuel filter changes and the expensive and time consuming task of cleaning diesel fuel tanks have become acceptable periodic maintenance instead of a warning signal for diesel engine failure. Diesel fuel filter elements should last a thousand hours or more, and injectors some 15,000 hours. However, since diesel fuel is inherently unstable, solids begin to form and the accumulating tank sludge will eventually clog your diesel fuel filters, ruin your injectors and cause diesel engines to smoke.
- Clogged and slimy filters
- Dark, hazy fuel
- Floating debris in tanks
- Sludge build up in tanks
- Loss of power and RPM
- Excessive smoke
- Corroded, pitted injectors
- Foul odor
The solids that form as the result of the inherent instability of the diesel fuel and the debris formed in the natural process of fuel degradation will accumulate in the bottom of your fuel tank. The sludge will form a coating or “bio-film” on the walls and baffles of the fuel tank, plug your fuel filters, adversely impact combustion efficiency, produce dark smoke from the exhaust, form acids that degrade injectors and fuel pumps, and impact performance. Eventually fouled diesel fuel will clog fuel lines and ruin your equipment.
But an even bigger picture is that In today’s world, defining how clean or dirty fuel is, is critically important and as such, fuel cleanliness levels are now measured and reported according to the ISO Cleanliness Code 4406:1999. The International Organization for Standardization (ISO) created the cleanliness code to quantify particulate contamination levels per milliliter of fluid at three sizes: 4μ, 6μ, 14μ. Microns.
Fuel Cleanliness vs. Engine Technology
Fuel cleanliness levels using the ISO4406:1999 method were officially documented as a global standard only as recently as 1998 with the development of the Worldwide Fuels Charter (WWFC). Since its inception, the charter has established a minimum cleanliness level for each of the diesel fuels under various available categories around the world.
Most mainstream engine OEM’s now subscribe to these standards. Interestingly, however, and somewhat troubling to note, is that fuel cleanliness levels being specified by engine OEM’s and the WWFC have not changed since their inception in 1998, despite the enormous advances in fuel injection technology. This relationship is best represented in the previous table that identifies the advances in fuel injection systems and clearly highlights how OEM’s and the WWFC have not responded to reduce fuel cleanliness in accordance with advancements in technology. Diesel Fuel Injection – Advancing Technologies & Cleanliness Levels
The table at the left identifies that over time, fuel injector critical clearances have halved and fuel pressures have doubled, yet the level of fuel cleanliness being specified has not changed in accordance with such advancements. In fact, the same cleanliness levels specified in 2000 are still being used today despite these magnificent technological design advancements by engine manufacturers worldwide.
Leading fuel injector manufacturers around the world have clearly identified and communicated that they require ULSD fuels with ISO fuel cleanliness levels as low as ISO12/9/6 to maintain ultimate performance and reliability. It is here where we see an enormous mismatch in what the fuel injection OEM desires as a fuel cleanliness level, to what the engine OEM’s and the WWFC are advising the industry. The following table identifies the discrepancies in fuel cleanliness levels.
Diesel Cleanliness Levels WWFC Diesel Category Fuel Cleanliness Standards
DAMAGE CAUSED BY HARD PARTICULATE
Hard particulate causes problems with moving parts in the fuel system. This can lead to starting problems, poor engine performance, idling issues and potentially complete engine failure.
All to common, hard particulates damage engines.
It must be extremely precise in terms of quantity, distribution and timing. Ball seat valves are sealed with balls that are only 1mm in diameter. A good seal is absolutely necessary for proper injection. Damage from erosive wear, such as shown below, will cause over fueling, leading to decreased fuel efficiency and eventually shut you down altogether.
So the bottom line is this: Nobody gets special fuel, nobody has better fuel, nobody has cleaner fuel…Diesel fuel vendors get the same fuel, from the same pipeline delivered to the same terminals. We all wait in the same lines with our tank trucks to get that same fuel, so what sets one vendor apart from all the others?
Star Oilco Premium Diesel fuel treated with Hydrotex PowerKleen® additive running through Donaldson filtration systems.
Next Blog Post: