Eurotherm
Invensys Operations Management
.

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