Fuel Oil: (CST180, CST280, CST380 / Bunker & Marine Fuels ) Types of Fuel Oil : Bunker & Marine Fuel Fuel Oil CST380 Fuel Oil CST280 Fuel Oil CST180 Furnance Oil Number 1: a volatile distillate oil intended for vaporizing pot-type burners. It is the kerosene refinery cut that boils off right after the heavy naphtha cut used for gasoline. Older names include coal oil, stove oil and range oil. Number 2: a distillate home heating oil. Trucks and some cars use similar diesel fuel with a cetane number limit describing the ignition quality of the fuel. Both are typically obtained from the light gas oil cut. Number 3: a distillate oil for burners requiring low-viscosity fuel. ASTM merged this grade into the number 2 specification and the term is rarely used. Number 4: a commercial heating oil for burner installations not equipped with preheaters. It may be obtained from the heavy gas oil cut. Number 5: a residual-type industrial heating oil requiring preheating to 170 – 220 °F (77 – 104 °C) for proper atomization at the burners. This fuel is sometimes known as Bunker B. It may be obtained from the heavy gas oil cut, or it may be a blend of residual oil with enough number 2 oil to adjust viscosity until it can be pumped without preheating. Also called Navy Special Fuel Oil, Navy Special or Furnace Fuel Oil. Number 6: a high-viscosity residual oil requiring preheating to 220 – 260 °F (104 – 127 °C). Residual means the material remaining after the more valuable cuts of crude oil have boiled off. The residue may contain various undesirable impurities including 2 percent water and one-half percent mineral soil. This fuel may be known as residual fuel oil (RFO), by the Navy specification of Bunker C, or by the Pacific Specification of PS-400. Also called Furnace Fuel Oil. Mazut: a residual fuel oil often derived from Russian petroleum sources and is either blended with lighter petroleum fractions or burned directly in specialized boilers and furnaces. It is also used as a petrochemical feedstock. Bunker Fuels : Bunker fuels are also a type of fuel oil, used aboard ships. Bunker fuel is often used as a synonym for No. 6 fuel oil which is the most common bunker fuel. Bunker A : No. 2 fuel oil Bunker B : No. 4 or 5 fuel oil Bunker C : No. 6 fuel oil Marine Fuels Other types of classification used in the maritime field also include : HFO : Heavy Fuel Oil IFO : Intermediate Fuel Oil MDO : Marine Diesel Oil MFO : Marine Fuel Oil MGO : Marine Gas Oil