The calculation of the uncertainty of the orifice-plate discharge coefficient

The present work is concerned a comparative study of the decay of swirling turbulent pipe flow downstream of three flow conditioners, the Etoile, the Tube bundle, and the Laws perforate plate, and its effect on accuracy of orifice plate flow meter. The swirl was generated by a double 90° degrees elbows in perpendicular planes. The discharge coefficients were measured with 3 different orifice meters with β = 0.5, 0.62, 0.70 at different Reynolds number. As a conclusion, the experimental study of the three flow conditioners used separately shows that the flow need longer distance for close to fully developed pipe flow and some errors, by reason of the swirl, on the discharge coefficient were inevitable for distance less 12D.

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Experimental Study of Various Porosity of Fractal Flow Conditioner for Orifice Plate Flowmeters

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.699.915 ◽

2014 ◽

Vol 699 ◽

pp. 915-920 ◽

Cited By ~ 1

Author(s):

Bukhari Manshoor ◽

Mohd Fahmi Othman ◽

Izzuddin Zaman ◽

Zamani Ngali ◽

Amir Khalid

Keyword(s):

Experimental Study ◽

Pressure Drop ◽

Mass Flow Rate ◽

Flow Rate ◽

Experimental Work ◽

Discharge Coefficient ◽

Orifice Plate ◽

Rate Data ◽

Plant Industry ◽

Measure Flow Rate

The plant industry is required to measure flow rate more accurately to meet plant operation and cost accounting objectives. The opposing concern of improving flow meter accuracy is resolved by using flow conditioners. The distance of implementation of flow conditioner upstream of the orifice plate flowmeter is also need to be addressed. Hence, in present study, an analysis of the porosity of fractal flow conditioner towards orifice plate flowmeter’s accuracy and the best distance of fractal flow conditioner upstream of the orifice plate flowmeter was determined. In an experimental work, a different porosity of the fractal flow conditioners were installed with different distance upstream of the orifice plate in conjunction with the different disturbances to assess the effects of these devices on the measurement of the mass flow rate. Data gained for all the plates showed that there is increment of pressure drop and change in discharge coefficient of the orifice with lower β value of fractal flow conditioner. Good comparisons with the previous experimental work demonstrate the fractal flow conditioner can preserve the accuracy of metering up to the level required in the standards.

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The Effect of Edge Sharpness on the Discharge Coefficient of an Orifice

Journal of Engineering for Power ◽

10.1115/1.3446067 ◽

1975 ◽

Vol 97 (4) ◽

pp. 576-581 ◽

Cited By ~ 3

Author(s):

R. P. Benedict ◽

J. S. Wyler ◽

G. B. Brandt

Keyword(s):

Optical Method ◽

Discharge Coefficient ◽

Empirical Equation ◽

Orifice Plate ◽

Radius Of Curvature ◽

Edge Sharpness

The effect of inlet edge roundness on the discharge coefficient of an orifice plate is studied experimentally. Several methods for measuring edge roundness are discussed and applied. An optical method in particular is shown to provide reliable measurements of edge roundness. Flow results are summarized in terms of radius of curvature by the empirical equation ΔCD/CD = 0.85 ln (rk/d × 103) + 1.74.

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Cavitation Effect on the Discharge Coefficient of the Sharp-Edged Orifice Plate

Journal of Basic Engineering ◽

10.1115/1.3662523 ◽

1960 ◽

Vol 82 (1) ◽

pp. 1-6 ◽

Cited By ~ 25

Author(s):

F. Numachi ◽

M. Yamabe ◽

R. O¯ba

Keyword(s):

Experimental Data ◽

Discharge Coefficient ◽

Cavitation Number ◽

Orifice Plate ◽

Cavitation Effect

The object of this paper is to investigate the effects of cavitation on the discharge coefficient of sharp-edged orifice plates with reference to various degrees of cavitation as defined by a cavitation number. The experimental data described in this paper substantiate the fact that cavitation can exist to a minimum cavitation number of 0.2 without introducing errors in the orifice discharge coefficient in excess of the normal expected accuracy. In addition to this, it was found that the use of air-inhalation to suppress the vibration and noise from the cavitation had no effect on the discharge coefficient.

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