Flow calculation for Venturi tubes

The ISO5167V application module is implemented against the ISO 5167-1:1991(E) Standard and provides the following functionality:

• Calculation and display of the mass and volume flowrates through Venturi tubes

• Calculation and display of the Reynolds number

• Four different tapping types

• Calculations for gas or liquid

• Standard supervisory workstation interface

• Standard software block

• Status and alarm display

• Engineer point display

• External conditions can be used to generate additional alarms

The ISO5167V application module forms part of a library of software function blocks designed to aid the implementation of flow calculation for Venturi tubes. The calculation is based on SI units (barG, °C and kg/hr)

Applications

The application module offers the functionality required to calculate mass and volume flowrates of fluids through Venturi tubes with either of the following tappings:

• As Cast

• Machined

• Rough Weld

• Nozzle

The module processes calibration and lab data and offers intermediate values such as corrected throat and pipe diameters.

Outline Specification

I/O

• Differential Pressure input

• Upstream Static Line Pressure input

• Upstream Line Temperature input

• Upstream Density input

Operator/Calibration Parameters

• Venturi Tube Calibration Diameter and Temperature

• Venturi Tube Expansion Factor

• Pipe Calibration Diameter and Temperature

• Pipe Expansion Factor

• Isentropic Exponent

• Dynamic Viscosity

• Relative Density

• Specific Heat Ratio

Alarms

• Diameter Ratio out of Range (Beta)

• Reynolds Number out of Range

Calculations

• Mass Flowrate

• Standard Volumetric Flowrate

• Corrected Venturi tube and Pipe Diameters

• Pressure Ratio

• Diameter Ratio

• Expansibility Factor

• Discharge Coefficient

• Reynolds Number

• Downstream Static Line Pressure

• Upstream Line Temperature