- Patel's Density Conversion for LPG from observed temperature to 15 C without use of ASTM Table (1980 series) Density unit Kg/m3

- Patel's Density Conversion for Liquefied Petroleum Gas (LPG)  from observed temperature to 15 C without use of  ASTM Table.  (Density unit Kg/m3).  

A separate post for the density unit Kg/L is given here. 

An exact conversion in Android /iOS App is given at the end of this article.

Following simple method help in easily converting LPG 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. 

LPG is transported in pipeline or marine tankers in cryogenic conditions and usually sample temperature is around 02 -15 deg C.

Two different alternate simplified ways are prescribed here. User may find their own alternative.

Option 1.    For LPG.  (Density range 5Xx  to 590  Sample Temperature range ----------. )

Simplified   Formula 

                        D₁₅ = d_o - ( 15  – t_o)  Where
                  

                           D15 =   Density at 15 deg C 

                  d_o = Density observed  Kg/m3

                  t_o   =  Temperature observed C

 B)  How to use formula manually without calculator

     

 Example : 1  LPG

       Density observed = 568  kg/m3

       Temp. observed   =  9 deg c

        ASTM table 53 B  =561.8 kg/m3

      

Steps :   1)   find difference  (15 - 9) manually ie.  6

              2)    Subtract  this  from observed density ie.  

                               568 - 6 =562    = 562.0 kg/m3+

              
                 ( Difference from ASTM table is 0.2 Kg/m3)

Example : 2.  LPG

                   Density observed = 585.3 kg/m3

                  Temp. observed   =  11.8  deg c

                   ASTM table 53 B  = 582.0 kg/m3

 Steps :   1)   find difference  (15 - 11.8) manually ie.  3.2

               2)   Subtract  this  from observed density ie.  

                                585.3 - 3.2 = 582.1   kg/m3.

  ( Difference from ASTM table is 0.1 Kg/m3)

Apps developed on Petroleum Calculations - see here.

Option 2.  For Propane,  Butane and LPG.  (Density range 500  to 600  Kg/m3,  Temperature range  -2  to 12 C)

Simplified   Formula 

                        D₁₅ = d_o  - 10 +  (   t_o – T)
       

  Density at 15 deg C= 
  Density observed  - 10 +  ( temp observed – T )

Where  value of T is :

Petroleum Product	T
Propane	6.0
Butane /LPG	5.5

   

B)  How to use formula manually without calculator

     

 Example : 1  LPG

       Density observed = 568  kg/m3

       Temp. observed   =  9 deg c

        ASTM table 53 B  = 561.8 kg/m3

      

Steps :   1)  subtract 10 from observed density    ie.  558 kg/m3

               2)  find difference  (   t_o – 5.5) manually ie.  3.5

              3)   Add this productto step 1 ie.  558  + 3.5 = 561.5 kg/m3

              ( Difference from ASTM table is 0.3 Kg/m3)

Example : 2.  LPG

                   Density observed = 585.3 kg/m3

                  Temp. observed   =  11.8  deg c

                   ASTM table 53 B  = 582.0 kg/m3

 Steps :   1)  subtract 10 from observed density    ie.  575.3 kg/m3

               2)  find difference  (   t_o – 5.5) manually ie.  6.3

              3)   Add this  to step 1 ie.  575.3  + 6.3 = 581.6 kg/m3

                    ( Difference from ASTM table is 0.4 Kg/m3)

The above is for ASTM Density Conversion tables of 1980 series.  

The equation given above was first developed in 1987 by author and since then extensively used for density conversion for pipeline, tanker and tank truck bullets   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 in Apps below:

The above Apps convert density from observed temperature to  15 C as well as 20 C.

                                       

Apps developed on Petroleum Calculations - see here.
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 rjpatelioc2014@gmail.com

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