API Gravity is typically used in reference to crude oil that is calculated using its specific gravity: the ratio of its density to that of water. The API sets standards for production, refinement and distribution of petroleum products including the method used for measuring the density of petroleum. An API gravity which is always determined at 60 °F is calculated: API gravity = (141.5/Specific Gravity) – 131.5. An API gravity is used to classify oils as light, medium, heavy, or extra heavy (Light – API > 31.1, Medium – API between 22.3 and 31.1, Heavy – API < 22.3, Extra Heavy – API < 10.0).
Related Definitions in the Project: The Process Engineering; Property and Unit
