Density Calculation from specific gravity

[Beginner - Inspector]

I want to calculate the density of crude and Kero Product , the Specific gravity is given at T & P, whether I have to multiply it with 1000kg /m3 (density of water @4 degree Celcius) or I have to find the density of water at that particular temperature and pressure and then multiply with SG.

PLEASE ADVISE !!!

 

[Snickster]

SG term is vague and outdated and therefore not codified, especially relevant to the gases. SG is rather informal and therefore the every working group can apply the different background behind that, given that every groupmember knows and applies SG in the same way as others do.
This is why the misinterpretation exists and why the specifications should be transfered between working groups (e.g. Contractor-Supplier) in a codified manner.

ASTM D3588-2017

3.1.5 relative density—the ratio of the density of the gaseous fuel, under observed conditions of temperature and pressure, to the density of dry air (of normal carbon dioxide content) at the same temperature and pressure.

GPA 2172-2002

3.2 Relative density - the ratio of the mass density of the gas at the measurement temperature and pressure to the density of dry air ... at the same temperature and pressure. Adjusting the result to the hypothetical ideal gas state converts the relative density into the molar mass ratio.

Both these statements simplify to SG gas = MWg/MWa using the ideal gas equation PV=mRT.

 

[shvet]

Both these statements simplify to SG gas = MWg/MWa using the ideal gas equation PV=mRT.

For ideal gases this works, for non-ideal - doesn't.

 

[Snickster]

True, not for different Z.