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