GPA 2172 : 2014

1 Scope
2 Normative References
3 Terms and Definitions
4 Symbols and Abbreviated Terms
5 Background
   5.1 Heating Value
   5.2 Relative Density
   5.3 Compressibility Factor
   5.4 Theoretical Hydrocarbon Liquid Content
6 Summary of Method
7 Equations for Custody Transfer Calculations
   7.1 Gross Heating Value (Volumetric Basis)
   7.2 Relative Density
   7.3 Compressibility Factor
   7.4 Theoretical Hydrocarbon Liquid Content
8 Example Calculations
9 Application Notes and Cautions
10 Precision and Uncertainty
Annex A (informative) - Details of Calculation Methods and
                        Treatment of Water
Annex B (informative) - Calculation of Gas Properties
Annex C (informative) - Water Content Example Calculations
Annex D (informative) - Calculation of NGL Energy Content from
                        Volume
Annex E (informative) - Determination of Gas Energy Content per
                        Unit Mass

Defines procedures for calculating, at base conditions from composition, the following properties of natural gas mixtures: gross heating value, relative density (real and ideal), compressibility factor and theoretical hydrocarbon liquid content which in the U.S. is typically expressed as GPM, the abbreviation for gallons of liquid per thousand cubic feet of gas.