API MPMS 14.3.3
Manual of Petroleum Measurement Standards Chapter 14 - Natural Gas Fluids Measurement Section 3 - Concentric, Square-Edged Orifice Meters Part 3 - Natural Gas Applications
|Publication Date:||1 January 1992|
This part of Chapter 14, Section 3, has been developed as an application guide for the calculation of natural gas flow through a flange-tapped, concentric orifice meter, using the inch-pound system of units. For applications involving SI units, a conversion factor may be applied to the results (Qm, Qv, or Qb) determined from the equations in 3.3. Intermediate conversion of units will not necessarily produce consistent results. As an alternative, the more universal approach specified in Chapter 14, Section 3, Part 1, should be used. The meter must be constructed and installed in accordance with Chapter 14, Section 3, Part 2.
Definition of Natural Gas
As used in this part, the term natural gas applies to fluids that for
all practical purposes are
considered to include both pipeline- and production-quality gas with
single-phase flow and mole
percentage ranges of components as given in American Gas Association
Measurement Committee Report No. 8, "Compressibility and
BASIS FOR EQUATIONS
The computation methods used in this part are consistent with those
developed in Part 1 and include
ORGANIZATION OF PART 3
Chapter 14, Section 3, Part 3, is organized as follows: Symbols and units are defined in 3.2, the basic flow equation is presented in 3.3, the key equation components are defined in 3.4, and the gas properties applicable to orifice metering of natural gas are developed in 3.5. All values are assumed to be absolute. Factors to compensate for meter calibration and location are included in Appendix 3-A. The factor approach to orifice measurement is included in Appendix 3-B. Appendix 3-C covers examples to assist the user in interpreting this part. Appendix 3-D covers pipe tap meters. Appendix 3-E covers SI conversions, Appendix 3-F covers heating value calculation, and Appendix 3-G covers derivation of constants. The user is cautioned that the symbols as defined in 3.2 may be different from those used in previous orifice metering standards.