Orifice Gas Flow Calculation Excel Spreadsheets

Posted on Friday, December 21, 2012 at 3:44 PM

Where to Find Orifice Gas Flow Calculation Excel Spreadsheets

If you are looking for orifice gas flow calculation excel spreadsheets, Click Here to visit our download page.  Why use online calculators or try to use the incredibly ong ISo 5167 equations for hand calculatons when you can buy a spreadsheet for gas flow, liquid flow, large bore or small bore, ISO 5167 orifice plate flow meter calculations at a very reasonable price.   Read on for information and discussion of the use of orifice gas flow calculation excel spreadsheets.

 

Background for Orifice Gas Flow Calculation Excel Spreadsheets

Background for Orifice Gas Flow Calculation Excel Spreadsheets

 

For background on orifice meters and the orifice coefficient, see the blog articles, "Excel Spreadsheets for Orifice and Venturi Flow Meter Calculations" and Calculate an Orifice Coefficient with ISO 5167."  The diagram at the left shows the general orifice meter configuration and some of the parameters used orifice gas flow calculation excel spreadsheets.  Equations from ISO 5167-2:2003 are presented in the next section.

 

 

 

Equations for ISO 5167 Orifice Gas Flow Calculation Excel Spreadsheets

Equations for ISO 5167 Orifice Gas Flow Calculation Excel Spreadsheets

 

The equations for pipes with diameter between 2 in and 40 in (50 mm to 1000 mm) are given in Reference #1 at the end of this article, ISO 5167-2:2003.  The equations are summarized here.  The commonly used equation for compressible fluid (gas) flow rate is shown at the right, where the parameters are defined as follows:

• Q is the flow rate through the pipe and orifice meter in cfs (m³/s for S.I. units)
• C_o is the orifice discharge coefficient, which is dimensionless
• A_o is the orifice  area in ft² (m² for S.I. units)
• P₁ is the upstream absolute pressure in the pipe in lb/ft² (kN/m² for S.I. units)
• P₂ is the pressure at the downstream pressure tap in lb/ft² (kN/m² for S.I. units)
• β is the D_o/D₁ = orifice diam./pipe diam., which is dimensionless
• Z is the compressibility factor of the gas at P₁, T₁
• R is the Ideal Gas Law Constant = 345.23 psia-ft³/slugmole-^oR    ( or 8.3145 kN-m/kgmole-^oK for S.I. units)
• MW is the molecular weight of the gas
• T₁ = upstream absolute temperature in the pipe, ^oR (^oK for S.I. units)    
• Y = Expansion factor  (see the equation for Y below)

Y  =  1  -  (0.351  +  0.265 β⁴ +  0.93 β⁸)[ 1 - (P₂/P₁)^1/k ]

where:  k is the Specific Heat Ratio (C_p/C_v) of the flowing gas

The orifice coefficient, C_o, can be calculated from the following equations:

Where Re is the Reynolds number in the pipe ( Re  =  DVρ/μ ).

 

Orifice Gas Flow Calculation Excel Spreadsheets

Orifice Gas Flow Calculation Excel Spreadsheets

 

The screenshot below shows an example of orifice gas flow calculation excel spreadsheets.  This spreadsheet can be used to calculate gas flow rate, required orifice diameter, or pressure difference across the orifice, if the other two parameters are known.  The orifice gas flow calculation excel spreadsheet shown if for large bore (2 in. to 40 in. diameter) and uses U.S. units.  The image shows just the worksheet to calculate gas flow rate.  Why bother to make these calculations by hand?  This Excel spreadsheet and other similar ISO 5167 orifice gas flow calculation excel spreadsheets are available in either U.S. or S.I. units at a very reasonable cost in our spreadsheet store.  There are also spreadsheets for large bore orifice meter calculations for liquid flow and for small bore orifice meter calculations (gas flow or liquid flow).  The small bore spreadsheets are for pipes with diameters between 12 inch and 1 1/2 inches (12 mm to 40 mm), and use slightly different equations from ASME MFC-14M:2001.

 

 

References:

1. U.S. Dept. of the Interior, Bureau of Reclamation, 2001 revised, 1997 third edition, Water Measurement Manual.

2. International Organization of Standards - Measurement of fluid flow by means of pressure differential devices inserted in circular cross-section conduits running full. Reference number: ISO 5167-2:2003.

3. Bengtson, Harlan H., Flow Measurement in Pipes and Ducts, An online continuing education course.

4. Bengtson, Harlan H., "Spreadsheets for ISO 5167 Orifice Plate Flow Meter Calculations," an online blog article.

5. Bengtson, Harlan H., "Orifice or Venturi Pipe Flow Meters: for Liquid Flow or Gas Flow," an Amazon Kindle ebook.