Tag Archives: venturi meter

ISO 5167 Venturi Meter Calculations with Spreadsheets

Posted on by
Reply

Where to Find ISO 5167 Venturi Meter Spreadsheets

For Excel spreadsheets to make ISO 5167 venturi meter calculations, click here to visit our spreadsheet store.  Obtain convenient, easy to use spreadsheets for ISO 5167 venturi meter calculations at reasonable prices. Read on for information about the use of Excel spreadsheets for venturi meter calculations.

How a Venturi Meter Works

Diagram for ISO 5167 Venturi meter calculationsVenturi meters function by sending pipe flow through a constricted area (the venturi throat), as shown in the diagram at the right.  Due to the increased fluid velocity passing through the constriction, there will be a decreased pressure at that location.   The pipe flow rate can then be calculated from the measured pressure difference between the undisturbed pipe flow and the flow through the constriction.

equation for ISO 5167 venturi meter calculationsA general equation for calculating flow rate through a venturi meter is shown at the left.  The parameters in the equation and their units are as shown below:

 

  • Q is the flow rate through the pipe and through the meter  (cfs – U.S. or m3/s – S.I.)
  • C is the discharge coefficient, which is dimensionless
  • A2 is the constricted area perpendicular to flow (calculated from the venturi throat diameter)  (ft2 – U.S. or m2 – S.I.)
  • P1 is the undisturbed upstream pressure in the pipe  (lb/ft2 – U.S. or N/m2 – S.I.)
  • P2 is the pressure in the pipe at the constricted area, Ao (lb/ft2 – U.S. or N/m2 – S.I.)
  • β = d/D = (diam. at A2/pipe diam.), which is dimensionless
  • ρ is the fluid density (slugs/ft3 – U.S. or kg/m3 – S.I.)

ISO 5167 Venturi Meter Guidelines

ISO 5167-4: 2003 provides discharge coefficient values for three venturi meter variations, subject to the venturi meeting a set of specifications and guidelines given in the publication.  The three venturi meter variations are i) “as cast” convergent section, ii) “machined” convergent section, and iii) “rough welded sheet iron” convergent section.  For each of these three variations, ISO 5167-4:2003 specifies a range for pipe diameter, diameter ratio (d/D), and Reynolds number in the pipe.

A Spreadsheet Screenshot for ISO 5167 Venturi Meter Calculations

The image below shows part of an Excel spreadsheet that can be used for ISO 5167 venturi meter calculations, such as flow rate calculation, discharge coefficient, pressure difference, or venturi throat diameter.  For this spreadsheet and other low cost, easy to use spreadsheets for gas flow or liquid flow ISO 5167 venturi meter calculations in S.I. or U.S. units, click here to visit our spreadsheet store.

screenshot of spreadsheet for ISO 5167 venturi meter calculations

 

References

1. Munson, B. R., Young, D. F., & Okiishi, T. H., Fundamentals of Fluid Mechanics, 4th Ed., New York: John Wiley and Sons, Inc, 2002.

2. U.S. Dept. of the Interior, Bureau of Reclamation, 2001 revised, 1997 third edition, Water Measurement Manual, available for on-line use or download at: http://www.usbr.gov/pmts/hydraulics_lab/pubs/wmm/index.htm

3. International Organization of Standards -Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full. Part 4, Reference number: ISO 5167-4:2003

4. Bengtson, Harlan H., “Orifice or Venturi Pipe Flow Meters: for Liquid Flow or Gas Flow,” an Amazon Kindle ebook.

5. Bengtson, Harlan H., “Flow Measurement in Pipes and Ducts,” an online, self-study, continuing education course for Professional Engineers at www.CEDengineering.com.

6. Bengtson, Harlan H., “Orifice and Venturi Meters Pipe Flow Meters – for Liquid and Gas Flow,” an online, self-study, continuing education course for Professional Engineers at www.suncam.com.

Orifice and Venturi Flow Meter Calculations Spreadsheet

Posted on by

Introduction to Orifice and Venturi Flow Meter Calculations Spreadsheet

For an orifice and venturi flow meter calculations spreadsheet, click here to visit our spreadsheet store.  Read on for information about Excel spreadsheets that can be used as orifice and venturi flow meter, pipe flow rate calculators.

Excel spreadsheets are convenient for differential pressure flow meter calculations,  for meters such as the commonly used orifice flow meter and venturi meter.  The general equation for differential pressure flow meters can be built into the spreadsheets with Excel formulas.  Also, for gas flow, the ideal gas law can be used to calculate the gas density based on its temperature, pressure, and molecular weight.  An Excel spreadsheet can also be used to calculate the orifice coefficient for anorifice meter with one of the ISO standard pressure tap configurations.

Background for an Orifice and Venturi Flow Meter Calculation Spreadsheet

Orifice and Venturi Flow Meter Calculations Spreadsheet diagramOrifice and venturi meters both function by sending pipe flow through a constricted area (the orifice plate or the venturi throat), as shown in the diagrams at the right.  Due to the increased fluid velocity passing through the constriction, there will be a decreased pressure at that location.   The pipe flow rate can then be calculated from the measured pressure difference between the undisturbed pipe flow and the flow through the constriction.

The general equation for calculating fOrifice and Venturi Flow Meter Calculations Spreadsheet Equationlow rate through either an orifice or venturi meter is shown at the left, where the parameters in the equation and their units are as follows:

 

  • Q is the flow rate through the pipe and through the meter  (cfs – U.S. or m3/s – S.I.)
  • Cd is the discharge coefficient, which is dimensionless
  • Ao is the constricted area perpendicular to flow  (ft2 – U.S. or m2 – S.I.)
  • P1 is the undisturbed upstream pressure in the pipe  (lb/ft2 – U.S. or N/m2 – S.I.)
  • P2 is the pressure in the pipe at the constricted area, Ao (lb/ft2 – U.S. or N/m2 – S.I.)
  • β = D2/D1 = (diam. at A2/pipe diam.), which is dimensionless
  • ρ is the fluid density (slugs/ft3 – U.S. or kg/m3 – S.I.)

Orifice and Venturi Flow Meter Calculations Spreadsheet Screenshot

The image below shows an Excel spreadsheet that can be used as a pipe flow rate calculator, based on the measured pressure difference across a flow nozzle, venturi, or Orifice flow meter.  This spreadsheet is suitable when the fluid density is known (as for a liquid) and the meter coefficient, C, is known.  For this spreadsheet and another to calculate the density of a gas using the ideal gas law model, click here to visit our spreadsheet store.

Orifice and Venturi Flow Meter Calculations Spreadsheet ScreenshotReferences

1. Munson, B. R., Young, D. F., & Okiishi, T. H., Fundamentals of Fluid Mechanics, 4th Ed., New York: John Wiley and Sons, Inc, 2002.

2. U.S. Dept. of the Interior, Bureau of Reclamation, 2001 revised, 1997 third edition, Water Measurement Manual, available for on-line use or download at: http://www.usbr.gov/pmts/hydraulics_lab/pubs/wmm/index.htm

3. International Organization of Standards – ISO 5167-1:2003 Measurement of fluid flow by means of pressure differential devices, Part 1: Orifice plates, nozzles, and Venturi tubes inserted in circular cross-section conduits running full. Reference number: ISO 5167-1:2003.

4. Bengtson, Harlan H., “Orifice and Venturi Flow Meters: for Liquid Flow and Gas Flow.” an Amazon Kindle e-book.