Measurement of gas flow by means of critical flow Venturi nozzles

2015 ◽  
Keyword(s):  
Gas Flow ◽  
Critical Flow

Field Calibration of Orifice Meters for Natural Gas Flow

1989 ◽  
Vol 111 (1) ◽  
pp. 22-33
Author(s):  
V. C. Ting ◽  
J. J. S. Shen
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Reynolds Numbers ◽  
National Standard ◽  
Test Facility ◽  
Critical Flow ◽  
Calibration Data ◽  
Discharge Coefficients ◽  
Sand Hills ◽  
Natural Gas Flow

This paper presents the orifice calibration results for nominal 15.24, 10.16, and 5.08-cm (6, 4, 2-in.) orifice meters conducted at the Chevron’s Sand Hills natural gas flow measurement facility in Crane, Texas. Over 200 test runs were collected in a field environment to study the accuracy of the orifice meters. Data were obtained at beta ratios ranging from 0.12 to 0.74 at the nominal conditions of 4576 kPa and 27°C (650 psig and 80°F) with a 0.57 specific gravity processed, pipeline quality natural gas. A bank of critical flow nozzles was used as the flow rate proving device to calibrate the orifice meters. Orifice discharge coefficients were computed with ANSI/API 2530-1985 (AGA3) and ISO 5167/ASME MFC-3M-1984 equations for every set of data points. The uncertainty of the calibration system was analyzed according to The American National Standard (ANSI/ASME MFC-2M-A1983). The 10.16 and 5.08-cm (4 and 2-in.) orifice discharge coefficients agreed with the ANSI and ISO standards within the estimated uncertainty level. However, the 15.24-cm (6-in.) meter deviated up to − 2 percent at a beta ratio of 0.74. With the orifice bore Reynolds numbers ranging from 1 to 9 million, the Sand Hills calibration data bridge the gap between the Ohio State water data at low Reynolds numbers and Chevron’s high Reynolds number test data taken at a larger test facility in Venice, Louisiana. The test results also successfully demonstrated that orifice meters can be accurately proved with critical flow nozzles under realistic field conditions.

Gravimetric Calibration of Critical Flow Venturi Nozzles

Volume 1 ◽  
2004 ◽  
Author(s):  
Thomas B. Morrow
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Discharge Coefficient ◽  
Computer Code ◽  
Critical Flow ◽  
Calibration Data ◽  
Sonic Nozzle ◽  
Flow Meters ◽  
Southwest Research Institute ◽  
Layer Flow

The Metering Research Facility (MRF) was commissioned in 1995/1996 at Southwest Research Institute for research on, and calibration of natural gas flow meters. A key commissioning activity was the calibration of critical flow Venturi (sonic) nozzles by a gravimetric proving process flowing nitrogen or natural gas at different pressures. This paper concerns the calibration of the four sonic nozzles installed in the MRF Low Pressure Loop (LPL). Recently, a new project prompted a review of the relations used to calculate sonic nozzle discharge coefficient in the LPL data acquisition computer code. New calibrations of the LPL sonic nozzles were performed flowing natural gas over a lower range of pressure than used in the original commissioning tests. The combination of new and old gravimetric calibration data are shown to agree well with correlations published by Arnberg and Ishibashi (2001) and by Ishibashi and Takamoto (2001) for laminar, transitional and turbulent boundary layer flow in critical flow Venturi nozzles.

Performance of a gas flow meter calibration system utilizing critical flow venturi standards

MAPAN ◽  
2011 ◽  
Vol 26 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Michael Carter ◽  
William Johansen ◽  
Charles Britton
Keyword(s):  
Gas Flow ◽  
Critical Flow ◽  
Calibration System ◽  
Flow Meter

The Choking Pressure Ratio of a Critical Flow Venturi

1975 ◽  
Vol 97 (4) ◽  
pp. 1251-1256 ◽  
Author(s):  
H. S. Hillbrath ◽  
W. P. Dill ◽  
W. A. Wacker
Keyword(s):  
Total Pressure ◽  
Gas Flow ◽  
Pressure Ratio ◽  
Critical Flow ◽  
Test Results ◽  
Flow Conditions ◽  
Pressure Losses ◽  
And Control ◽  
Measurement And Control ◽  
Effectiveness Parameter

The critical flow venturi has many important applications in the measurement and control of gas flow. In many of these applications, it is desirable to minimize the pressure loss required to maintain critical flow conditions. The performance of the venturi may be characterized by the ratio of outlet static pressure to inlet total pressure just sufficiently small to produce critical flow. This ratio is called choking pressure ratio (CPR). The optimization of diffusers for critical flow Venturis is discussed and suggestions for designs practice are presented. Test results are given for six different diffuser configurations, and a comparison is made with data on 11 configurations from other investigators. This work was done under contract to the National Aeronautics and Space Administration—Marshall Space Flight Center. It is shown that, for the small divergence angles considered, a simply defined diffuser effectiveness parameter is approximately independent of flow conditions and may be used to predict choking pressure ratio. Even very short diffusers greatly improve performance, and, for longer diffusers, critical flow can be maintained at total pressure losses of 5 percent.

Calibration of High Pressure Gas Meters with Sonic Nozzles

1972 ◽  
Vol 5 (11) ◽  
pp. 440-446 ◽  
Author(s):  
M G Peignelin
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Pressure Effect ◽  
Critical Flow ◽  
Gas Flow Rate ◽  
A New Technique ◽  
Cylindrical Throat ◽  
Working Out ◽  
Venturi Nozzle

At present, gas meters are calibrated under low pressure with standard Bell provers. As the meters can be used under high pressure on the network, the pressure effect upon the error curve must be determined. To avoid this drawback, we have been searching for another standard of gas flow rate at the Gaz de France test station which disposes of a natural gas having steady characteristics and capable of operating at a pressure of 50 bar and a flow rate about 12 000 m3/h (N). This study led us to the working out of a new technique based upon a critical flow meter: the venturi nozzle with a cylindrical throat. This paper presents: the results of the sonic nozzles calibration a description of the equipment composed of sonic nozzles to calibrate meters and some examples of the use of this standard of flow rate.

Research on the Coaxial Connection between Gas Flowmeter and Critical Flow Venturi Nozzle Gas Flow Standard Device

2016 ◽  
Vol 693 ◽  
pp. 194-199
Author(s):  
Yang Zhen
Keyword(s):  
Gas Flow ◽  
Critical Flow ◽  
Measurement Instruments ◽  
Flow Meter ◽  
Standard Device ◽  
Value Transfer ◽  
Important Measurement ◽  
Venturi Nozzle

As an important measurement instruments of trade metering, gas flowmeter has been more and more widely used, and the quantity value transfer of the flow meter is becoming increasingly significant. In order to realize the accurate measurement, the method of the coaxial connection between gas flowmeter and critical flow Venturi nozzle gas flow standard device is studied in this paper, and the coaxial error between this gas flowmeter and standard device within ±1mm is achieved.

High-accuracy stable gas flow dilution using an internally calibrated network of critical flow orifices

2010 ◽  
Vol 21 (11) ◽  
pp. 115902 ◽  
Author(s):  
P J Brewer ◽  
B A Goody ◽  
T Gillam ◽  
R J C Brown ◽  
M J T Milton
Keyword(s):  
Gas Flow ◽  
High Accuracy ◽  
Critical Flow
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