Emerson Process Management ControlWave XFC - Manual (Page 130)

F-28 / Appendix F CI-ControlWave XFC
Pipe Temp. Coefficient - Pipe coefficient of thermal expansion is entered here (Inches per
Inch-degree F).
Isentropic Exponent - Gas Isentropic Exponent is entered here. This should not be
changed unless the Gas Isentropic Exponent is known to be other than the 1.3 value given
in the 1992 American Gas Association (AGA3) Report.
Adjust Press. - Users enter Average Barometric Pressure here (psia).
Diff. Press. - Actual value in use is displayed here.
Static Pressure - Actual value in use is displayed here.
Temperature - Actual value in use is displayed here.
Spec. Gravity - Specific Gravity of the gas being measured is displayed here.
Z Flowing - Flowing compressibility Factor, Zf, generated from the AGA8 calculation
referenced to upstream conditions.
Z Base - Base compressibility Factor from the AGA8 Gross calculation.
Base Temperature - Required and Contract Base Temperate is entered here (Deg. F).
Base Pressure - Required or Contract Base Pressure is entered here (psia).
The following outputs from the AGA3 calculation are displayed:
MSCF/H - Flow rate in thousands of standard cubic feet per hour
Low Flow Cut Off - Cutoff (if the DP drops below the low flow cut off value) or OK
C Prime - Orifice Flow Constant
Fn - Numeric Conversion factor which includes Ev (the velocity of approach factor)
CD - Orifice Coefficient of Discharge
Y - Expansion Factor
Fpb - Pressure Base Factor
Ftb - Temperature Base Factor
Ftf - Flowing Temperature Facture
Fpv - Supercompressibility Factor
Fm - Additional Correction Factor
Extension - Square Root of the product of Diff. Pressure and Static Pressure (
)
Reynolds Number - Computed Pipe Reynolds Number