The material contained in this appendix is for clarification and general information only.
Physical Properties of Ammonia
Molecular symbol NH3
Molecular weight 17.031
Boiling point at one atmosphere*-28°F
Melting point one atmosphere*-107.9°F
Critical temperature 271.4°F
Critical pressure 1657 psia
Latent heat at -28°F and one atmosphere* 589.3 Btu/lb
Relative density of vapor compared to dry air at 32°F and one atmosphere*0.5970
Vapor density at -28°F and one atmosphere*0.05555 lb/ft3
Specific gravity of liquid at -28°F compared to water at 39.2 °F 0.6819
Weight per gallon of liquid at -28°F5.69 lbs/gallon
Liquid density at -28°F and one atmosphere42.57 lbs/ft3
Specific volume of vapor at 32°F and one atmosphere20.78 ft3/lb
Flammable limits by volume in air at atmospheric pressure16% to 25%
Ignition Temperature (in a standard quartz container) 1562° F
Specific Heat, Gas, at 59°F and one atmosphere*
at constant pressure, Cp0.5232 Btu/lb° F
at constant volume, Cv 0.3995 Btu/lb° F
*One atmosphere = 14.7 psia
Wis. Admin. Code Department of Safety and Professional Services, SPS 301-399, SPS 326-360, ch. SPS 343, app APPENDIX