However, if the value of API gravity is less than 10, it implies that the liquid is heavier than water and will sink. If the API gravity of a liquid is greater than 10° API, the liquid will float on water.
The behavior of the crude products in water is judged based on this parameter. The API gravity for pure water in that case will be: The API gravity is often compared with water such that, the relative density of heavy oil at 60☏ is taken as 1.0, the same value as for pure water. Therefore, one can directly calculate API gravity from density. Where the density of water is taken as 999 kg/m³. The specific gravity of the liquid can be estimated from its density the same way as in our specific gravity calculator using the equation below: However, it is often used with a degree symbol, such as the degree of API gravity (° API). The API gravity parameter is dimensionless, based on the equation. The above equation can also be called the specific gravity to the API conversion formula. The API gravity of a crude product is related to the specific gravity using the equation: You can make ads in the Engineering ToolBox more useful to you Densities, molecular weight and chemical formulas of some common gases can be found in the table below: 1) NTP - Normal Temperature and Pressure - is defined as 20oC (293.15 K, 68oF) and 1 atm ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 30 in Hg, 760 torr) 2) STP - Standard. The specific gravity is then used in the API gravity formula. To find the API gravity of a liquid, initially, the relative density is calculated using a hydrometer or an oscillating U-tube conforming to industry standards ASTM D1298 or D4052. The API gravity is calculated based on the specific gravity of the liquid. The term API in API gravity stands for American Petroleum Institute, with reference to the institution that developed it. The API gravity is a measure of the heaviness of crude oil products when compared with water.