Title: Gas Flow Orifice Meter Calculations
Contributor: Harlan Bengtson, Ph.D., P.E. , Former Dean of Engineering, Southern Illinois University Edwardsville
Published Date: December/2015
Content Type: Spreadsheet
Orifice meters, which are widely used for flow measurement in pipes, require a value for the orifice coefficient for most calculations. ISO 5167 and ASME MFC-14M standards provide a means for calculating the orifice coefficient with reasonable precision for specific pressure tap configurations, but require an iterative calculation for either flow rate of the fluid or required orifice diameter. This Excel workbook facilitates these iterative calculations for gas flow.
This workbook includes worksheets for calculating:
1) fluid flow rate for specified pipe diameter, orifice diameter and measured pressure difference
2) required orifice diameter for specified pipe diameter, fluid flow rate and pressure difference
3) pressure difference for specified pipe diameter, orifice diameter, and fluid flow rate
Each of these calculations may be made using ISO 5167 equations (for pipe diameters from 2" to 40"), ASME MFC-14M equations (for pipe diameters from 0.5" to 1.5"), or with a user specified value for the orifice coefficient. There is also a worksheet containing the needed gas properties for 21 gases.