U.S. Energy Information Administration logo

Glossary

A B C D E F G H I J K L M N O P Q R S T U V W XYZ

Browse terms related to these fuel groups:alternative fuels|coal|electricity|natural gas|nuclear|petroleum|renewable

Residual fuel oil

Residual fuel oil:  A general classification for the heavier oils, known as No. 5 and No. 6 fuel oils, that remain after the distillate fuel oils and lighter hydrocarbons are distilled away in refinery operations. It conforms to ASTM Specifications D 396 and D 975and Federal Specification VV-F-815C. No. 5, a residual fuel oil of medium viscosity, is also known as Navy Special and is defined in Military Specification MIL-F-859E, including Amendment 2 (NATO Symbol F-770). It is used in steam-powered vessels in government service and inshore powerplants. No. 6 fuel oil includes Bunker C fuel oil and is used for the production of electric power, space heating, vessel bunkering, and various industrial purposes.

Top