The major measuring equipment in this test is pycnometer. Specific gravity relative density sg is a dimensionless unit defined as the ratio of the density of a substance to the density of water at a specified temperature and can be expressed as. Both density and specific gravity describe mass and may be used to compare different substances. Specific gravity and api gravity are both measurements of density. Api gravity is related to the specific gravity by the following equation. This test is done to determine the specific gravity of finegrained soil by density bottle method as per is. You find the sp gravity difference between the two liquids by subtraction, and find the percentage of the difference based on the individual volumes of the samples. The average value of specific gravity of the tested soil sample equals to 2. They are many common crude types like west texas, brent api gravity is a measure of.
Specific gravity is an expression of density in relation to the density of a standard or reference usually water. Specific gravity of soil by pycnometer methodprocedure. The ratio of the weight of a given volume of oil at 20c to the weight of an equal volume of water at 20c. Light crude oil is defined as having an api gravity higher than 31.
This is a glass jar of 1 litre capacity that is fitted at its top by a conical cap made of brass. Of all the physiochemical properties, the specific gravity has been reported most frequently in the literature. Based on this formula, the newly formed electrolyte fluid would have a specific gravity of 1. The measuring scale is calibrated in terms of degrees api. The gas specific gravity calculation does not check for unreasonable inputs. Specific gravity, ratio of the density of a substance to that of a standard substance. The formula for specific gravity, given that the reference substance is water, is the density of the object divided by the density of the water. In physics, the weight of the substance differs from its mass. How to find the specific gravity when two liquids are.
Use the online api to specific gravity converter to find the sp gr of an oil by providing the api gravity. Equations for gas specific gravity and molecular weight conversion. It is the evidence of cohesion between the particles of a fluid which causes a liquid to offer resistance analogous to friction. Api gravity temperature correction online calculator. This information can be used to tell whether lube oil will float or sink if dropped in water buoyancy. Api gravity to specific gravity and density chart if you need need to convert other value use our online api gravity calculator on the top. Gases are commonly compared with dry air, which has a. Specific gravity sp gr measures the ratio of density of the substance to the density of water in a given temperature, i. Or we can define in another way ie, mass of fuel oil consumed per average shaft power developed by the engine at.
This follows from the formula of specific gravity where sg density oildensity water. How to convert specific gravity in weight sciencing. S m m air, where sgas specific gravity, mgas molecular weight, m air 28. How to calculate the specific gravity of a substance dummies. Specific gravity is often defined relative to water, in which case the specific gravity of air is 0. The specific gravity of the liquid used in this case is a volumetric average value calculated from the reservoirs and the completion fluids specific gravities. The specific gravity of gasoline is less than 1, which means that it has a density less than water and is lighter than water. Viscosity and specific gravity values from coleparmer.
See correlations at density of crude oil as function of temperature. Specific gravity can also be defined relative to the density of air, in which case the. Composite specific gravity sg comp the composite specific gravity of oil and water mixture can be calculated if the individual fluids specific gravities and percentages are known. When taking specific gravity measurements, it is important to correct for temperature to get a true reading. It can be calculated by comparing the weight, mass and density of the given object with water of the same amount at 4 0 c. The above table shows the actual hydrometer readings of acid at a specific gravity of 1.
In the metric system specific gravity is the same as in the english system. Above 45 degrees the molecular chains become shorter and less valuable to refineries. Api gravity calculator crude oil api gravity chart. Generally speaking, oil with an api gravity between 40 and 45 commands the highest prices. Use the online api to specific gravity converter to. Specific gravity formula for liquids definition, formula. The official formula used to derive the gravity of petroleum liquids from the specific gravity sg, as follows. Viscosity property of a liquid that resists any force tending to produce flow. It should be noticed that the value of specific gravity changes with temperature, so we tried to maintain the value of. The specific gravity stands for a dimensionless unit that defines the ratio of density of a substance to the density of water. The arbitrary formula used to obtain this effect is. Specific gravity gives information about the weight and density of the object. Specific gravity is a dimensionless parameter that represents the ratio of the density a substance to the density of water at 4 degrees celsius. He also shows how to calculate the value for specific gravity and use it to determine the percent of an object that will be submerged while floating.
This means that the volume of a petroleum liquid increases with increasing temperature, and that a density number always must be given with the measurement. Specific gravity is the ratio of the weight in air of a given volume of a material at a standard temperature to the weight in air of an equal volume of distilled water at the same stated temperature. Crude oil density vs temperature posted in refining, hydrocarbons, oil, and gas. Api gravity express the gravity or density of crude oil and liquid petroleum products. The weight is the gravitational force that pulls any object to earth. You will learn how to calculate density and how to use density to calculate volume or mass. Specific gravity of soil test civil engineering community.
The density of water is kgcubic meters at 4 celsius. Specific fuel oil consumption definition consumption of fuel oil per unit energy at out put shaft is known as specific fuel oil consumption. They both can be used to measure the gravity of a fluid, such as hydraulic oil, in the same way that miles or kilometers can both be used to measure distance. Oil with the least specific gravity has the highest api gravity. Read our article titled viscosity and specific gravity values from coleparmer. A specific gravity scale developed by the american petroleum institute api for measuring the relative density of various petroleum liquids, expressed in degrees. Relative density, or specific gravity, is the ratio of the density mass of a unit volume of a substance to the density of a given reference material. To support you, coleparmer is open for business and shipping product daily. It is common to use the density of water at 4 oc 39 of as a reference since water at this point has its highest density of kgm 3 or 1. Specific gravity and density oil and gas separator. The dimensionless ratio of the density of a material to that of the same volume of water.
It is clear from table 1 in the theory part that the test was done on a sand sample of soil due to the range of the values of specific gravity. The hemp cannabis sativa seed oil is extracted from seed. The importance of specific gravity dynamix agitators. Specific gravity can be calculated from api gravity. Specific gravity is a concept that shows up in a variety of industrial applications, particularly as it relates to fluid dynamics. Mass specific gravity of a substance is the ratio of density of the substance to the density of standard substance. Because the density of water at 4 degrees celsius is 1,000 kgm3, that ratio is easy to find. It was analysed by percentage ash, refractive index, specific gravity, acid value, iodine value, saponification number, unsaponifible mater content and peroxide number. Determine the specific gravity of soil civil engineering.
Specific fuel oil consumption sfoc definition,formula. As a rule of thumb, specific gravity will change by 0. The specific gravity of this mixture is calculated as shown in the following equation. For example, if youve ever taken your car in for service and the mechanic showed you how small plastic balls floated in your.
Api gravity increases with increasing temperature, while specific gravity decreases with increasing temperature. If two fluids have largely different density, or include a solids component, they will be much more resistant to mixing. The specific gravity of a gas is the ratio of the density of the gas to the density of air at standard conditions of temperature and pressure. The specific gravity can be found by dividing the density of gold by the density of water at 4. The formula to correct a reading for any hydrometer calibration temperature is as follows.
Use our api gravity to density to convert to specific gravity. Api gravity change with temperature for crude oils. Multiply the specific gravity of the oil by the density of water to obtain the density of the oil. In this video david explains what specific gravity means. Api is devised jointly by the american petroleum institute and the nist national institute of standards and technology. Unit of specific fuel oil consumption is kgkwh or gbhph. It may be related to the molecular weight by the following equation. The additional data requirements for napls include. It was examined for physical and chemical properties. In physics, a substances specific gravity is the ratio of that substances density to the density of water at 4 degrees celsius. Im searching for a method that gives me the density of a crude oil in first approximationgiven his api gravity. Specific gravity is the heaviness of a substance compared to that of water, and it is expressed without units.
Fluid specific gravity an overview sciencedirect topics. The specific gravity of lube oil is the ratio of the density of lube oil to that of a reference substance usually water. Most common minerals have specific gravities between 2 and 7. The relative density of petroleum liquids can also be uncovered by using api gravity value.
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