3.1 Accurate knowledge of the weight and volume of butadiene is necessary for the orderly manufacture, storage, transfer, and sale of the material. These tables are suitable for use in these and similar aspects of butadiene commerce.

Enter the table in the column for “Observed Relative Density,” headed 0.640, and note that against an “Observed Temperature” of 40 °F, the corresponding relative density 60/60 °F is

 
0.627

Likewise, note that for 0.645 specific gravity opposite 40 °F, the corresponding relative density 60/60 °F is

0.632

This represents an increase of 0.005 in relative density 60/60 °F for an increase of 0.005 in the value at 40 °F. Therefore, by simple proportion, an increase in the specific gravity value noted at 40 °F from 0.640 to 0.642 increases the corresponding relative density 60/60 °F by 0.4 × 0.005 or

 
0.002

Then, the relative density 60/60 °F corresponding to the observed relative density of 0.642 at 40 °F is 0.627 + 0.002 or

0.629

Enter the table in the column for “Specific Gravity 60/60 °F'' headed 0.625, and note that against an “Observed Temperature'' of 35 °F the factor is

 
1.027

Hence, 1 U.S. gal of butadiene of relative density 0.625 at 60/60 °F and measured at 35 °F occupies a volume at 60 °F of

1.027 U.S. gal

Then 45 500 U.S. gal measured at 35 °F occupy a volume at 60 °F of 45 500 × 1.027 or

46 728 U.S. gal

WEIGHT PER UNIT VOLUME AT 15.6 °C (60 °F) AGAINST SPECIFIC GRAVITY 60/60 °F

The following equation expresses the relationship between relative density (60/60 °F) and the corresponding density in pounds per U.S. gallon in vacuum:

lb/gal = RD60/60 × Density of Water at 60 °F in g/cm³ × g/cm³ to lb/gal conversion

or

lb/gal = RD60/60 × Density of Water at 60 °F in lb/gal

Solve equations above with values of D60/60 and round the result to nine places past the decimal for further use as per API MPMS 11.5.2

EXAMPLE

A tank car of 1,3 butadiene having a relative density 60/60 °F of 0.627 is determined to contain 24 386 U.S. gallons at 60 °F

D 60/60 °F in lb/gal = 0.627 × 0.999 016 × 8.345 404 452 = 5.227 419 743 91 lb/gal. The 24 386 U.S. gallons of 1,3 butadiene is then equivalent to (rounded as per API MPMS 11.5.2):

Weight in vacuo = 5.227 419 744 lb/gal x 24 386 gal =127 475.86 lb

A tank of 10 000 U.S. gal capacity is observed to contain 1500 gal of liquid at 95 °F and consequently 40.1 psi gauge pressure and an observed relative density of 60/60 °F 0.627. The volume of butadiene vapors in the tank is obviously 10 000 − 1500, or

 
8500 U.S. gal

Entering the table with either the temperature of 95 °F, or the gauge pressure of 40.1 psi, the volume of 60 °F butadiene liquid in each volume of vapor space is

 
0.01404

Then 8500 U.S. gal multiplied by 0.01404 gives the amount of butadiene in the vapor space expressed as U.S. gallons of 60 °F butadiene liquid and is

 
119.3 gal

This 121.0 gal of 60 °F butadiene liquid that is in the vapor space can be added to the liquid contents of the tank expressed as U.S. gallons of 60 °F butadiene to obtain the total contents of the tank.

From Table 2 the factor to correct the 1500 gal from 95 °F and a relative density of 0.627 to 60 °F is 0.961; therefore, the liquid content of the tank in U.S. gallons at 60 °F is 0.961 × 1500

 
1441.5 gal

The total contents of the tank in U.S. gallons at 60 °F is 119.3 + 1441.5 or 40.1

1560.8 gal

The table can also be entered with the temperature of 95 °F or gauge pressure of 40.1 psi reading the vapor density in air of

0.0734 lb/gal

The weight of butadiene in the vapor space of 8500 U.S. gal is therefore (8500 × 0.0734)

623.9 lb

From Table 2 the 1500 gal of liquid of 0.627 relative density and 95 °F is multiplied by the factor of 0.961 to obtain the amount of butadiene  at 60 °F (1500 × 0.961)

 
1441.5 gal

From API MPMS 11.5.2, the 1441.5 gal of butadiene at 60 °F with a relative density of 0.627 is noted to weigh 5.218189479 lb/gal; therefore, the weight of liquid butadiene is 1441.5 × 5.218148479

 
7521.7 lb

The total weight of butadiene in the tank is 623.9 + 7521.96

8145.6 lb

1.1 The ASTM Butadiene Measurement Tables are for use in the calculation of quantities of butadiene. The accompanying Tables 1-3 cover the normal operating ranges for the reduction of observed relative density and volume to 15.556/15.556 °C (60/60 °F) and for the calculation of weight-volume relationships of butadiene.

1.2 These tables are applicable to both butadiene and butadiene concentrates (minimum of 60 % butadiene).

Note 1: These tables replace the existing tables in the National Institute of Standards and Technology Letter Circulars LC-736 and LC-757 and the Rubber Reserve Corp., Butadiene Laboratory Manual.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.