API gravity of oil products
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As the title suggests, what does the API rating of oil mean?
A method to indicate the specific gravity of oil: API=145/0.8—135
I made a mistake; it’s 145/Density—135
141.5/density-131.5 seems to be it
API gravity is a measure used to indicate the density of oil and petroleum products; it is also known as specific gravity index in the petrochemical industry. It is used to express the relative density of liquids. API gravity = 141.5/d – 131.5, where d is the relative density at 15.6°C. Generally, crude oil with an API gravity of ≥32 is considered light crude oil, that with an API gravity of 20–32 is medium crude oil, that with an API gravity of 10–20 is heavy crude oil, and that with an API gravity less than 10 is very heavy crude oil. The higher the API gravity, the lighter the crude oil, and thus its price is higher.
API, also known as the specific gravity index, is another way of expressing the density of crude oil in Europe and the United States. If d(15.6, 15.6) is used to represent the relative density of crude oil at 15.6°C, then: API = 141.5/d(15.6, 15.6) – 131.5
A unit established by the American Petroleum Institute (API) to indicate the density of petroleum and petroleum products. The United States and China use the API degree as a benchmark for classifying crude oil (see Crude Oil Evaluation). The standard temperature for this is 15.6°C (60°F), and the relationship between API and the relative density at 15.6°C (compared to water) is given by: API = (141.5/relative density) – 131.5. As can be seen from this formula, the higher the API degree, the lower the relative density. Currently, the API degree is regarded internationally as one of the main criteria for determining crude oil prices. The higher its value, the lighter the crude oil and the higher its price.
In my mind, it’s the US standard, an indicator of the density of the oil! ;P
The US standard and the national standard differ only in terms of density; the API calculation formulas use the density at 15.6°C, while the density values used in refinery analyses are those at 20°C. It needs to be converted to 15.6 in order to be used
How to convert the density at 20°C to the density at 15.6°C?