C104 – API Volumetric Flow Rate of Natural Gas at Standard Conditions (Factors Approach Method) 1992
Description
This calculates the volumetric flow rate of natural gas at standard conditions using the ‘Factors Approach’ method outlined in the MPMS Chapter 14.3.3 Appendix 3-B.
References
FLOCALC Calculation reference F034
Kelton calculation reference C024
Kelton calculation reference C104
Manual of Petroleum Measurement Standards Chapter 14 – Natural Gas Fluids Measurement, Section 3 – Concentric, Square-Edged Orifice Meters, Part 3 – Natural Gas Applications, Appendix 3-B – Factors Approach (Third Edition 1992; Reprinted 2009)
Calculations
Calculation as documented in standard
Volumetric Flow Rate
The volumetric flow rate is calculated from:
| Where | ||
|---|---|---|
| Fc | = | Orifice calculation factor |
| Fgr | = | Real gas relative density factor |
| Fn | = | Numeric conversion factor |
| Fpb | = | Base pressure factor |
| Fpv | = | Supercompressibility factor |
| Fsl | = | Orifice slope factor |
| Ftb | = | Base temperature factor |
| Ftf | = | Flowing temperature factor |
| Y1 | = | Expansion factor |
| Pf1 | = | Upstream pressure in psi |
| hw | = | Orifice differential pressure in inH2O (60°F) |
| C’ | = | Composite flow factor |
Orifice Calculation Factor
The numeric conversion factor, Fc, is calculated from:
| Where | ||
|---|---|---|
| D | = | Pipe diameter at flowing temperature in inches |
| β | = | Orifice diameter ratio |
| ReD | = | Reynolds number of pipe flow |
Real Gas Relative Density Factor
The real gas relative density factor, Fgr, is calculated from:
| Where | ||
|---|---|---|
| Gr | = | Real gas relative density |
Numeric Conversion Factor
The numeric conversion factor, Fn, is calculated from:
| Where | ||
|---|---|---|
| d | = | Orifice bore diameter at flowing temperature in inches |
| β | = | Orifice diameter ratio |
Base Pressure Factor
The base pressure factor, Fpb, is calculated from:
| Where | ||
|---|---|---|
| Pb | = | Base pressure in psi |
Supercompressibility Factor
The supercompressibility factor, Fpv, is calculated from:
| Where | ||
|---|---|---|
| Zb | = | Base supercompressibility factor |
| Zf1 | = | Line supercompressibility factor |
Slope Factor
The slope factor, Fsl, is calculated from:
| Where | ||
|---|---|---|
| β | = | Orifice diameter ratio |
| ReD | = | Reynolds number of pipe flow |
Base Temperature Factor
The base temperature factor, Ftb, is calculated from:
| Where | ||
|---|---|---|
| Tb | = | Base temperature in °R |
Flowing Temperature Factor
The flowing temperature factor, Ftf, is calculated from:
| Where | ||
|---|---|---|
| Tf | = | Flowing temperature in °R |