- Patel's Density Conversion for Petroleum Products from observed temperature to 15 C without use of ASTM Table (1980 series) , (a Scholarly article)

- Patel's Density Conversion for Petroleum Products from observed temperature to 15 C without use of  ASTM Table

Following simple method help in easily converting petroleum products density to 15 deg C, without using ASTM Tables, and without help of calculators. It is very handy for field persons who are taking density for comparing parent density for Quality Control purpose. 

This method is developed for temperate area where ambient/sample temperature is normally 27 +/- 5  deg C.    For colder area,  see formula in a different post in this blog. 

Difference from this method comparing to actual ASTM table is usually after decimal point that also less than 0.4 kg/m³ one need to remember that usually persons read hydrometers and thermometers without considering the eye approximation between digits, which any way cause error of more than 0.4 kg/m³ . 

A)   Simplified   Formula 

                        D₁₅ = d_o  + 10 +  C  x (   t_o – T)

  Density at 15 deg c   = Density observed   + 10 + Constant x ( temp observed – T )

   Temperature unit is Deg C and Density unit is kg/m³

 Where  C and T are :

Product	C  = Constant	T
Gasoline  / Naphtha	0.9	26
Kerosine  /  Jet A-1	0.7	28.5
Gasoil	07	29.5

Apps developed on Petroleum Calculations - see here.

B)  How to use formula manually without calculator

     

 Example : 1  Gasoline

       Density observed = 727.0  kg/m³

       Temp. observed   =  30 deg c

        ASTM table 53 B  = 740.4 kg/m³

      

Steps :   1)  add 10 to observed density    ie.  737.0 kg/m³

               2)  find difference  (   t_o – T) manually ie.  4

              3)   multiply difference and constant  ie.  4 x 0.9 = 3.6         

              4) Add this product to step 1 ie.  737.0 + 3.6 = 740. 6 kg/m³

Example : 2.  Jet A-1

                   Density observed = 792.0 kg/m³

                  Temp. observed   =  31 deg c

                   ASTM table 53 B  = 803.6 kg/m³

 Steps :   1)  add 10 to observed density    ie.  802.0 kg/m³

               2)  find difference  (   t_o – T) manually ie.  2.5

               3)   multiply difference and constant  ie.  2.5 x 0.7 = 1.7         

               4) Add this product to step 1 ie.  802.0 + 1.7 = 803.7 kg/m³

Example : 3, Gasoil

                   Density observed = 834.0 kg/m³

                  Temp. observed   =  27 deg c

                  ASTM table 53 B  = 842.3 kg/m³

Steps :   1)  add 10 to observed density    ie.  844.0 kg/m³

              2)  find difference  (   t_o – T) manually ie.  (-2.5)

              3)   multiply difference and constant  ie.  -2.5 x 0.7 = -1.7         

             4) Add this product to step 1 ie.  844.0 - 1.7 = 842.3 kg/m³

The above is for ASTM Density Conversion tables of 1980 series.  Some industry still use old series ie ASTM 1952.

The equation given above was first developed in 1987 by author and since then extensively used for density conversion for pipeline, tanker and aviation tank truck   samples outside Laboratory/office where it is a bit inconvenient to take out ASTM table Book for density conversion.

The reader may please remember here that author's idea is to convert observed density to 15 deg C density in field with accuracy and simplicity,   however for exact conversion as per ASTM table 53 B can be found below:

http://rjpatelioc-petroleum.blogspot.in/2016/12/density-conversion-to-15-deg-c-table.html

                                         

Above link provide excel worksheet for a simple Cell entry to know Density at 15 C, exactly as ASTM table.         

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 rjpatelioc2014@gmail.com

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