The ratio of two liquified gas propellants required to deliver a given vapor pressure for an aerosol can be estimated from the physical properties for the two propellants.


If the equations from the previous example are rearranged:


percent for first propellant (as a whole number from 0 to 100) =

= 100 / (1 + Y)


Y =

= ((desired vapor pressure in psi for mixture) – (vapor pressure for first propellant in psig)) / ((vapor pressure for second propellant in psig) - (desired vapor pressure in psi for mixture)) * (molecular weight of second propellant in grams) / (molecular weight for first propellant in grams)


percent for second propellant =

= 100 – (percent for first propellant)


To read more or access our algorithms and calculators, please log in or register.