Gas which may be placed in a container for determining the length of a fixed dip tube is determined by multiplying the maximum volume of liquefied petroleum gas obtained by the formula in paragraph (b)(19)(b) of this section by the pounds of liquefied petroleum gas in a gallon at 40 deg. F. for aboveground and at 50 deg. F. for underground containers. For example, typical pounds per gallon are specified below:
Example: Assume a 100gallon total water capacity tank for aboveground storage of propane having a specific gravity of 0.510 of 60 deg. F.
[(100 (gals.) X 42 (filling density from subparagraph (12) of this paragraph))divided by(0.510 X 1.031 (correction factor from Table H29) X 100)] = (4200 divided by 52.6)
(4200 divided by 52.6) = 79.8 gallons propane, the maximum amount permitted to be placed in a 100gallon total water capacity aboveground container equipped with a fixed dip tube.
[(Maximum volume of LPGas (from formula in subdivision (b) of this subdivision) X 100) divided by Total water content of container in gallons] = Maximum percent of LPGas
Example: Assume a 100gallon total water capacity tank for aboveground storage of propane having a specific gravity of 0.510 of 60 deg. F.
[(100 (gals.) X 42 (filling density from subparagraph (12) of this paragraph))divided by(0.510 X 1.031 (correction factor from Table H29) X 100)] = (4200 divided by 52.6)
(4200 divided by 52.6) = 79.8 gallons propane, the maximum amount permitted to be placed in a 100gallon total water capacity aboveground container equipped with a fixed dip tube.
[(Maximum volume of LPGas (from formula in subdivision (b) of this subdivision) X 100) divided by Total water content of container in gallons] = Maximum percent of LPGas
Aboveground, pounds per gallon 
Underground pounds per gallon 

Propane  4.37  4.31 
N Butane  4.97  4.92 