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QAF 011b | Rev. 10 | 26-12-13
©2014 Haward Technology Middle East
This document is the property of the course instructor and/or Haward Technology Middle East. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of Haward Technology Middle East.
P.O. Box 26070, Abu Dhabi, UAE Tel: +971-2-59 69 400 Fax: +971-2-59 69 401 Email: [email protected] http://www.haward.org
Distribution Network Automation Volume 1
Haward Technology Middle East
April 06-10, 2014 Dharan, KSA Course Instructor Mr. Sydney Thoresson
Liquid & Gas Flowmetering
To the Participant
The Course Notes are intended as an aid in following lectures and for review inconjunction with your own notes; however they are not intended to be acomplete textbook. If you spot any inaccuracy, kindly report it by completingthis form and dispatching it to the following address, so that we can take thenecessary action to rectify the matter.
Haward Technology Middle EastP.O. Box 26070Abu Dhabi, UAE
Tel.: +971 2 59 69 400Fax: +971 2 59 69 401Email: [email protected]
Name
Address
Course Title
Course Date
Course Location
Descriptionof Inaccuracy
Disclaimer
The information contained in these course notes has been compiledfrom various sources and is believed to be reliable and to representthe best current knowledge and opinion relative to the subject.
Haward Technology offers no warranty, guarantee or representationas to its absolute correctness or sufficiency.
Haward Technology has no responsibility in connection therewith;nor should it be assumed that all acceptable safety and regulatorymeasures are contained herein, or that other or additionalinformation may be required under particular or exceptionalcircumstances.
Table of Contents Section 1 Introduction to
Process Measurement Section 2 Flow Measurement
Section 3 Differential Pressure
Flowmeters
Section 4 Variable Area Flowmeters
Section 5 Oscillatory Flow Measurement
Section 6 Rotary Inferential Flowmeters
Section 7 Electromagnetic Flowmeters
Section 8 Positive Displacement Flowmeters
Section 9 Ultrasonic Flowmeters
Section 10 Mass Flowmeters
and Selection
Section 11 Miscellaneous Devices
Section 12 Flowmeter Calibration
Table of Contents Section 13 Flowmeter Installation Guidance Section 14 Flowmeter Costs and Flowmeter
Selection
Section 15 Introduction to Multiphase Flow Measurement
Section 16 Basic Concepts of
Multiphase Flow and Multiphase Flowmeter
Section 17 Current Main Suppliers of Multiphase Flowmeters
Section 18 Level Measurement
Section 19 Selection of Flowmeters
Section 20 OIML Recommendation 117
Section 21 Terminal Custody Transfer
Section 22 Lease Automatic
Custody Transfer
Table of Contents
Section 23 Truck Custody Transfer
Section 24 Leak Detection Systems
Section 25 API Standards
Section 26 Standards Organizations, Flow Measurement Standards and References
Section 27 Contoured Devices
Section 28 a. Computer System Control A b. Computer System Control B
Section 1
Introduction to Process Measurement
Page 1 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Liquid & Gas Flow Metering
Course Objectives
Upon the successful completion of this course, each participant will be able to:
Apply an in-depth knowledge and skills in liquid and gas multiphase and single-phase flowmetering, ultrasonic flowmetering, custody measurement and loss control of petroleum products
Select and calibrate an ultrasonic flowmeter for the required application and deal with related operational and measurement concerns
Choose the correct flowmeter or combination of flowmeters for a particular multiphase application and be able to resolve any ensuing problems in relation to unreliability or inaccuracy of flowmeter readings
Compare the performances of existing multiphase meters such as Agar, Weatherford, Roxar, Schlumberger and Haimo and recognize their importance in flowmetering
Determine the different types, methods and techniques used in custody transfer and understand the various pipeline meter considerations
Employ systematic techniques in leak detection and loss control during custody transfer and list the various API standards applicable to flowmetering and custody measurement
Page 2 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Table of Contents Section 1 Introduction to Process Measurement Section 2 Pressure Measurement Section 3 Temperature Measurement Section 4 Flow Measurement Section 5 Differential Pressure Flowmeters Section 6 Variable Area Flowmeters Section 7 Oscillatory Flow Measurement Section 8 Rotary Inferential Flowmeters Section 9 Electromagnetic Flowmeters Section 10 Positive Displacement Flowmeters Section 11 Ultrasonic Flowmeters Section 12 Mass Flowmeters Section 13 Miscellaneous Devices Section 14 Flowmeter Calibration Section 15 Flowmeter Installation Guidance Section 16 Flowmeter Costs and Flowmeter Selection Section 17 Quality Assurance and Standards Section 18 Introduction to Multiphase Flow Measurement Section 19 Basic Concepts of Multiphase Flow and Multiphase Flowmeters Section 20 Current Main Suppliers of Multiphase Flowmeters Section 21 Selection of Flowmeters Section 22 Future Developments in Flow Measurement Section 23 Numerical Exercises Section 24 Standards Organisations, Flow Measurement Standards and References Section 25 Cavitation and Flashing Section 26 Pipeline Requirements and Installation Notes for Dry-type
Differential Transmitters Section 27 Contoured Devices
Page 3 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Section 1
Introduction to Process Measurement
Process Measurement
Conversion of a physical parameter • temperature/pressure/level/flow
To a standard, widely-recognised signal • Pneumatic
‐ 3 - 15 psi; 20 - 100 kPa • Electrical level (voltage/current)
‐ 4 - 20 mA; 0 - 10 V • Digital code
‐ HART/Profibus PA; Foundation Fieldbus
Analog Inputs
Page 4 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Measurement Accuracy
How closely does the output signal represent the actual parameter?
(what is the uncertainty of the measurement)
Expressing Accuracy
% of Reading % of Full-scale
Accuracy
Page 5 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Range of Operation
High and Low Operating Limits between which the device will operate
correctly.
Hysteresis
Accuracy of device dependent on previous value and the direction of variation.
Page 6 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Linearity
How close the curve is to a straight line.
Repeatability
How close a second measurement is to the first under the same
operating conditions and the same input.
Response
Output of a device expressed as a function of time due to an applied
input.
Page 7 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Typical Response to a Step Input
Effects of Temperature
Accuracy (uncertainty) may be specified over a certain temperature range (e.g. 10o - 60oC)
Temperature effect may be quoted as x %/oC
Effects of Time
Shows an instrument’s ability to maintain its stability over time Typical periods quoted as 60, 90, 180, 360 days, etc
• 10 - 12 years for recent instruments
Page 8 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Traceability
Capability of providing an unbroken paper chain back to the original, primary standard
Relative or total? Is the accuracy/uncertainty only relative to the next higher instrument a in the chain, or absolute, including all uncertainties back to the primary a standard?
Confidence Level
The percentage of devices which meet specification is called the ‘confidence level’
• A top manufacturer may specify that 99% of instruments meet the specification
Not all instruments meet the specification
Resolution
The ability to ‘resolve’ a minimum difference between two readings On an analog meter, the scale difference between two adjacent lines In a digital instrument, the smallest step between one reading and the
next higher or lower value
Noise Level
Most process instruments have an output with random variations These variations interfere with the reading
Calibration
A comparison of a measurement against an equal or better device, and adjusting the instrument to agree with the better device.
Budget
Important Selection Consideration! Price usually dictates performance
Page 9 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
What are we Measuring?
meters (m) - length or distance kilograms (kg) - mass seconds (s) - time Amperes (A) - electrical current Degrees Kelvin (oK) - temperature Moles (mol) - amount of any substance Candela (cd) - intensity of light
Instrumentation Representation on Flow Diagrams
Page 10 of 10
Section 1 IE250-IH
Liquid & Gas Flowmetering
Letter Codes and Balloon Symbols
Symbols for Transducers, etc.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 2
Flow Measurement
Page 1 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Section 2
Pressure Measurement
Principles
Pressure = Force per unit area Units are psi, mm Hg and kPa, etc. Absolute Pressure referenced to a vacuum Gauge Pressure referred to ambient atmospheric pressure Differential Pressure compares two different pressures
Pressure Units
Page 2 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Pressure Sources Static Pressure
Due to weight of the molecules “pressing down”. Dynamic Pressure
Relative movement when a body is moving through the fluid.
Static Pressure
Dynamic Pressure
Page 3 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Pressure Variations
Total Pressure
Pressure Transducers – Mechanical
Bourdon Tube Helix and spiral tubes Spring and Bellows Diaphragm Manometer Single and Double Inverted Bell
Page 4 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
C - Bourdon Tube
Bent tube will change its shape when exposed to variations in internal or external pressure
Orientation dependent for correct results Wide Operating range
C - Bourdon Pressure Element
Advantages of C – Bourdon
Inexpensive Wide Operating Range Fast response Good sensitivity Direct Pressure measurement
Page 5 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Disadvantages of C-Bourdon
Intended for indication only Non-linear transducer Hysteresis on cycling Sensitive to temperature variations Limited life under shock/vibration Some materials clog the tube Unstable zero point
Application Limitations
Use in air if calibrated for air Use in liquid if calibrated for liquid Bleed air from the liquid lines If for Oxygen, device cannot be calibrated if it leaves oil traces oil
Helix and Spiral Tubes
With one end sealed, pressure causes the tube to straighten out Spiral suitable up to 28 000 kPa Helical suitable up to 500 000 kPa
Spiral Bourdon Element
Page 6 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Helix Bourdon Element
Advantages - Spiral/Helix
Increased accuracy and sensitivity Higher over-range protection
Disadvantages - Spiral/Helix
Very Expensive
Spring and Bellows
Expandable element Free end responds to pressure Spring used to oppose force Linkage to pointer for indication Primarily for ON / OFF control Provides contacts for electrical circuits Responds to pneumatic or hydraulic pressure changes
Page 7 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Spring and Bellows Switch
Page 8 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Spring and Bellows Gauge
Advantages - Spring/Bellows
Simple construction Easily maintained Inexpensive
Disadvantages - Spring/Bellows
Sensitive to temperature variations Work hardening of bellows Hysteresis Poor over-range protection
Diaphragm
Sensor measurement dependent on deflection of diaphragm Flexible disc Flat or with concentric corrugations Sheet metal with high tolerance dimensions
Page 9 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Simple Corrugated Diaphragm
Advantages – Diaphragm
Provide isolation from process fluid Good for low pressure Inexpensive Wide range Reliable and proven Used to measure gauge, atmospheric and differential pressure
Manometer
Simplest form is U-shaped, liquid filled tube Reference and measured pressure applied to ends of tube Difference in pressure causes difference in liquid level between sides
Page 10 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Simplest Form of Manometer
Typical Applications
Mainly spot checks or calibration • Modern calibration using electronic meters
Low range measurements • Higher measurements require mercury
‐ toxic, therefore hazardous
Advantages – Manometer
Simple operation and Construction Inexpensive
Disadvantages - Manometer
Low pressure range (water) Higher pressure range requires mercury Readings are localised
Page 11 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Application Limitations
Size limits operation to low range Difficult to integrate into continuous control system
Single and Double Inverted Bell
Measures pressure difference between sides of bell shaped compartment To reference to surrounding conditions
• Lower compartment vented to outside • Gauge pressure measured
Inverted Bell d/p Detector
The bell instrument is used where very low pressures are to be measured, typically 0 - 250 Pa
Page 12 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Pressure Transducers and Elements
Strain gauge Vibrating wire Piezoelectric Capacitance Linear Variable Differential Transformer Optical
Strain Gauges
Metal wire or semiconductor chip Change in resistance as metal is deformed by pressure Temperature sensitive
• Temperature compensation required • Often use Wheatstone bridge
Wheatstone Circuit for Strain Gauges
Page 13 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Typical Application
Force • Applied to diaphragm • Through silicone fill fluid • To polysilicon sensor
Reference side exposed to atmospheric pressure for gauge transmitters
Advantages - Strain Gauges
Wide range, 7.5 kPa to 1 400 MPa Accuracy of 0.1% Small in size Stable devices with fast response No moving parts Good over-range capability
Disadvantages - Strain Gauges
Unstable due to bonding material Temperature sensitive Thermo-elastic strain causes hysteresis
Vibrating Wire
Electronic oscillator circuit causes natural frequency oscillation of wire Wire under tension in diaphragm Pressure changes cause changes in natural frequency
Advantages - Vibrating Wire
Good accuracy and repeatability Stable Low hysteresis High resolution Absolute/gauge/differential measurement
Page 14 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Disadvantages - Vibrating Wire
Temperature sensitive Affected by shock and vibration Non-linear Physically large
Piezoelectric
Crystals elastically deformed when force applied Measure rate of change of deformation Electrical output proportional to applied acceleration
Advantages – Piezoelectric
Accuracy 0.075% Very high pressure measurement, up to 70 MPa Small size Robust Fast response, < 1 nanosecond Self-generated signal
Disadvantages - Piezoelectric
Dynamic sensing only Temperature sensitive
Capacitance
Diaphragm movement causes capacitance change Sensor energised by a high frequency electrical oscillator Relative capacitance measured by bridge circuit
Page 15 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Capacitance Measurement
Advantages – Capacitance
Accuracy 0.01 to 0.2% Range of 80Pa to 35MPa Linearity Fast response
Page 16 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Disadvantages - Capacitance
Temperature sensitive Stray capacitance problems Vibration Limited overpressure capability Cost
Cross Section of the Rosemount -CellTM Sensor
Linear Variable Differential Transformer (LVDT)
Movement of high permeability material within transformer coils Pressure transferred via diaphragm, bellows or bourdon tube
Page 17 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Linear Variable Differential Transformer
Disadvantages
Mechanical wear Vibration
Optical Pressure Sensor
Page 18 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Optical
Opaque vane mounted to the diaphragm Vane moves in front of infra-red beam Received light indicates position of the diaphragm
Advantages – Optical
Temperature corrected Good repeatability Negligible hysteresis
Disadvantages - Optical
Expensive
Installation considerations
Location of Connections Isolation Valves Impulse Tubing Test and Drain Valves Construction Temperature Remote Diaphragm Seals Precautions with Remote Diaphragm Seals Process Flanges Additional Hardware
Location of Process Connections
Top of process line for gases Side of lines for other fluids
Isolation Valves
Between process fluid and measuring equipment if device is to be taken out
Page 19 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Use of Impulse tubing
Impulse piping • Short as possible • Self draining by sloping lines towards the process
Self venting instruments If solids can accumulate place tees and plug fittings in place of elbows
Test and Drain Valves
Blowdown valve needed for toxic or corrosive fluid
Sensor Construction
Mechanical and thermal isolation: • Away from process flange • Position in neck of electronics housing
Temperature Effects
Wheatstone bridge often used to compensate for temperature effects
Remote Diaphragm Seals
Remote seals needed if: • Corrosion is possible • Fluid viscosity may cause clogging • Process temperature is outside normal operating temperature of
transmitter • Fluid may solidify • Fluid needs to be flushed • Maintaining sanitary or aseptic conditions • Making density or other measurements
Page 20 of 20
Section 2 IE250-IH
Liquid & Gas Flowmetering
Precautions with Remote Seals
Large diameter/short capillary • minimises temperature effects
In two seal system use same • fluid • diaphragm diameter • capillary length
Fluid to cope with extremes of temp and pressure
Process Flanges
Coplanar flange • Becoming more standard
Traditional flange • traditional biplanar configurations
Level flange • Permits direct process mounting
Additional Hardware
If pulsation dampeners are required the material and fill fluids must be compatible with the process fluid
Siphons of correct material required for vapours above 60oC
Impact on the Control Loop
Longer response due to material build-up on sensing element Over-ranging causing incorrect readings
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 3
Differential Pressure Flowmeters
Page 1 of 14
Section 3 IE035-IH
Liquid & Gas Flowmetering
Section 3
Temperature Measurement
Principles
Transfer of heat energy from the process material to the measuring device
Two main types • Contact (Thermocouples, RTDs and Thermistors) • Non-contact (Infra red and Acoustic)
Thermocouples
Two wires of dissimilar metals • Iron/constantan connected at one end
Application of heat to junction • Creates a voltage between the two wires
A reference junction is placed in series with the sensing junction
Page 2 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Extension/Compensating Cable
Extension cable • same metals as thermocouple junction • used with base metal thermocouples
Compensating cable gives the same effect • copper alloy in both conductors • cheaper alternative • used with noble metal thermocouples
Averaging Temperatures
Temperature Difference
Page 3 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Construction
Installation Techniques
Use largest size thermocouple wire possible Avoid stress and vibration Use transmitters if possible
• Thermocouples are mV signals • Susceptible to noise • 4 - 20 mA signals almost noise-immune
Detection of Thermocouple Faults
Short in the extension wires may not be detected Measure resistance continuously to note any changes
Application Details
Thermopaste minimises air-gap problems Clean bore of thermowell when changing
New thermocouple of different mass/length to old one means longer response time
Grounding requires care
Page 4 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Thermocouple Voltage Curves
Applications
R-type thermocouples are suitable in oxidising atmospheres easily contaminated in others
T-type can be used in oxidising or reducing atmospheres J-type can be used in reducing atmospheres. Least expensive K-type can be used in oxidising atmospheres
Page 5 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Advantages
Low cost Small size Robust Wide range of operation Reasonably stable Reasonable output for large temperature changes Fast response
Disadvantages
Weak output, mV Limited accuracy
• Usually accepted as being 3% Sensitive to electrical noise Non-linear
• Complex conversion from emf to temp
• Not an issue with -processor inputs
Application Limitations
Small temperature changes mean very small voltage changes Susceptible to noise Non-linear Calibration changes over time Cannot be used bare in conductive fluids
Page 6 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Thermocouple Colour Coding
Platinum Resistance Thermometers (RTD)
Platinum construction (usually) Electrical resistance increases with temp
Temperature coefficient in ohms/°C
• Usual figure of = 0.385/OC Fairly linear but temperature coefficient does vary Pt100 and Pt1000 Ni100 and Ni1000
Page 7 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Two/Three/Four Wire Measurement
Page 8 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Typical Applications
Pt100 housed in thermowell 2-wire used in HVAC applications
• Provided very short runs used 3-wire used in industrial applications 4-wire in high precision environment
Advantages
Good sensitivity Standard copper wire
• From Pt100 to indicator/controller Mostly linear
• Up to 1000C • Non-linear (but predictable) after that
Disadvantages
Somewhat fragile • Pt wire wound on glass
‐ Similar expansion coefficients Self heating considerations Susceptible to noise
Comparative Transfer Curves
Page 9 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Thermistors
Semiconductor device formed from metal oxides Negative temperature coefficient Size from 1mm to a few cm disc Small temperature change easy to detect
Thermistor Resistance vs Temperature
Page 10 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Typical Thermistor Packaging
Selection and Sizing
-73 °C to 316 °C Many cannot be used above 120 °C
Advantages
Small size Fast response High sensitivity No cold junction compensation Inexpensive Polarity insensitive Wide selection of sensors
Page 11 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
Unstable due to drift and de-calibration Not easily interchangeable Non-linear Narrow span Fragile High resistance, noise problems
Liquid-in-glass Thermometer
Page 12 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Class II B Vapour Filling
Bi-metal Strip
Page 13 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Non-contact Pyrometers
Infra-red pyrometers Acoustic Pyrometers
Objects Above Absolute Zero Radiate
Page 14 of 14
Section 3 IE250-IH
Liquid & Gas Flowmetering
Structure of Humicap Sensor
Protect Thermocouple Signal
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 4
Variable Area Flowmeters
Page 1 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Section 4
Flow Measurement
Types of Flow
Newtonian vs Non-Newtonian Flow
Page 2 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Laminar Flow
Fluid moves smoothly in orderly layers. Little or no mixing of fluid across flow stream.
Turbulent Flow
Does not move smoothly in orderly layers. Large amount of mixing of fluid across flow stream.
Flow Profiles
Swirl
Occurs as fluid passes through elbows or some other form of pipeline geometry.
Reynolds Number
Reynolds Number defines the flow conditions at a particular point. Useful indicator of laminar and turbulent flow.
Page 3 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Reynolds Number
Volumetric Flow Rate
Represents the volume of fluid which passes through a pipe per unit of time.
Mass Flow Rate
Mass flowrate is a measure of the actual amount of mass of the fluid passing through a pipe per unit of time.
Totalised Flow
An accumulation of the amount of fluid that has past a point in a pipe.
Viscosity
Defines the resistance which the fluid has against flowing.
Dynamic Viscosity has the units of cP (CentiPoise).
Kinematic Viscosity = / has the units of cSt (CentiStokes).
Page 4 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Density
The density of a fluid is the mass of the fluid per unit volume. Density is affected by temperature and pressure variations.
Specific Gravity
The weight of a substance may vary for the same volume or size. The Specific Gravity is the ratio between the density of a substance to
the density of water.
Pulsations
To maintain good measuring conditions, pulsations in the flow stream should be recognised and (if possible) avoided.
Cavitation
Occurs when pressure is reduced below vapour pressure of the liquid. Vapour cavities, or bubbles subsequently form.
Non-Newtonian
Normal behaviour of fluids is such that as temperature increases, viscosity decreases.
Non-Newtonian fluids do not conform to the normal behaviour of liquids. They may become thinner or thicker when agitated or stiffen when
deformed.
Vena Contracta
The cross-sectional area of a fluid decreases as it is forced through a restriction.
This area continues to decrease for a short time after the restriction. The Vena Contracta is the minimum cross-sectional area of the fluid.
Page 5 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Vena Contracta
Rangeability
Page 6 of 6
Section 4 IE250-IH
Liquid & Gas Flowmetering
Turndown
Flow Measurements
Velocity Volumetric Flow Mass Flow Total Flow
Volumetric Flow
Mass Flow W = Q . p Where: Q is the volumetric flow rate. p is the density of the fluid. W is the mass of the flow rate.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 5
Oscillatory Flow Measurement
Page 1 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Section 5
Differential Pressure Flowmeters
Basis of Operation
Pressure is measured on both sides of an imposed restriction in the path of normal flow.
Some Useful Equations
V = k . (Dp/r)
Q = k . A . (Dp/r)
W= k . . A . (Dp/r) V = Velocity Q = Volumetric flow rate
= Fluid density W = Mass flow rate
p = Differential pressure A = Cross-sectional area of the pipe k = a constant
Page 2 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Head Loss
Primary Element
Standard Orifice Plate is smooth disc with a round, sharp-edged inflow aperture and mounting rings.
Page 3 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Differential Pressure Profile with Orifice Plate
Orifice Type
Three main types of orifices: • Concentric square edged. • Concentric quadrant edged. • Eccentric or segmental square edged.
New type is 4-hole conditioning orifice plate See details later for this.
Page 4 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Concentric Orifice Plate
Quadrant Edge Orifice Plate
Page 5 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Segmental Orifice Plate
Advantages
Simple, inexpensive Requires no calibration (new) Easily fitted between flanges No moving parts Large range of sizes and opening ratios Suitable for most gases and liquids Well understood and proven Price not much more for large lines
Disadvantages
Accuracy typically > 1.5% Low turndown, typically 4:1
Accuracy is affected by , P and Damage to restriction affects accuracy Unrecoverable pressure loss Viscosity limits measuring range Straight runs of pipe required upstream
Page 6 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Application Limitations
Inaccuracies due mainly to process conditions; temperature and pressure variations
Upstream and downstream piping Standard concentric orifice plates should not be used for slurries and
dirty fluids
Venturi Tube
Fluid accelerated through a nozzle shaped inflow piece (converging cone) which induces a local pressure drop.
Fairly high cost of Venturi Tube.
Venturi Tube
Page 7 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Venturi Tube Advantages
Less significant pressure drop across restriction Less unrecoverable pressure loss Requires less straight pipe
Disadvantages
More expensive Bulky, requires large section for installation
Flow Nozzles
Similar to venturi but shape of ellipse. Higher flow capacity than orifice plates.
Flow Nozzle used Mainly in High Velocity Applications
Advantages
High Velocity Higher turbulence Suspended solids More cost effective than venturi Smaller than venturi
Page 8 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
More expensive Higher unrecoverable pressure loss
Dall Tube
More compact than venturi Higher differential pressure for less unrecoverable pressure loss Low loss meter
Dall Tube Low Loss Meter
Advantages
Shorter length Lower unrecoverable pressure loss
Page 9 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
More complex to manufacture Sensitive to turbulence Accuracy based on flow data
Application Limitations
Should be calibrated with piping section in which it is to be used Calibrate over full range of flows
Pitot Tube
Measures flow based on differential pressure Primarily gas flows, but also liquid flows Small tube directed into the flowstream to get total pressure Second measurement of static pressure Difference gives dynamic pressure
Page 10 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Basic Form of Pitot Static Tube
Advantages
Low cost Low permanent pressure loss Ease of installation into existing systems
Disadvantages
Low accuracy Low rangeability Clean liquid, gas or vapour only
Multiport Pitot Averaging
Multi-impact opening type and improves accuracy of this type of measurement.
Used to compensate for changes in the velocity profile.
Page 11 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Multiport “Annubar” Pitot Averaging System
Elbow
Pipe Elbow can be used as primary device Viable differential pressure device Tappings at 22.5º provide more stable readings 45º tappings more suited to bidirectional flow measurement
Elbow Meter Geometry
Page 12 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Flow in a Pipe Bend
Advantages
Simplified installation Inexpensive
Disadvantages
Low accuracy
Primary Element Advantages
No moving parts Large range of sizes and opening ratios Suitable for most gases and liquids Well understood and proven. Price does not dramatically increase with size
Page 13 of 13
Section 5 IE250-IH
Liquid & Gas Flowmetering
Primary Element Disadvantages
Accuracy affected by density; pressure and viscosity Erosion and physical damage to restriction affects measurement Unrecoverable pressure loss Viscosity limits measuring range Require straight runs of pipe Square law characteristics
Secondary Element
Differential Pressure transmitter Most common inaccuracy is not allowing enough straight pipe
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 6
Rotary Inferential Flowmeters
Page 1 of 2
Section 6 IE250-IH
Liquid & Gas Flowmetering
Section 6
Variable Area Flowmeters
Variable Area Flowmeters
Low viscosity liquids at high velocities.
Flow stream displaces a float placed in the stream.
Page 2 of 2
Section 6 IE250-IH
Liquid & Gas Flowmetering
Viscosity Limits of Rotameters Depend on Float Shape
Selection and Sizing
Actual flow has to be converted into standard flow Not affected by piping configurations For 25mm bore the cost comparable to magmeter
Advantages
Inexpensive Wide range of applications Very basic operation Easy installation and simple to replace Linear scale
Disadvantages
Limited accuracy Subject to density, viscosity and temperature changes Fluid must be clean Erosion of device Expensive for large diameters Operate in vertical position only Viscosity > 200 cP
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 7
Electromagnetic Flowmeters
Page 1 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Section 7
Oscillatory Flow Measurement
Vortex Meter
Relationship between K-factor and Reynolds number
Page 2 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Round Bluff Bodies
Delta Shaped Bluff Bodies
Two Part Bluff Body
Page 3 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Rectangular Bluff Body
Construction of Typical Vortex Precession (Swirl) Meter
Page 4 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Coanda Flowmeter
Generates internal oscillations similar to an electronic oscillator. Oscillations are generated by feeding part of the mainstream flow back
into itself.
Diagram of Mode of Operation of Feedback Oscillator
Secondary Element
A number of devices can be used to measure the vortex frequency • Thermistors • Pressure Sensors • Magnetic Pick-up • Strain Gauge • Piezoelectric • Capacitive
Page 5 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Installation Techniques
Fully developed flow is required for good measure-ment. Meter should be installed upstream of any disturbance. Straight lengths of pipe can be reduced by fitting a flow straightener.
Advantages
Suitable for liquid, gas or steam Can be used for non-conductive fluids No moving parts, low maintenance Sensors available for gas and liquid
Not affected by , , P or temperature Low installation cost Good accuracy Linear response
Disadvantages
Uni-directional measurement only Clean fluids only Not suitable with partial phase change Not suitable for viscous liquids Straight pipe runs required for installation
Application Limitation
Upstream and downstream requirements of straight pipe vary according to a number of factors
• Severity and nature of disturbance upstream • Severity and nature of disturbance downstream • Type of vortex bluff body (the specific design of the meter) • The accuracy required
Page 6 of 6
Section 7 IE250-IH
Liquid & Gas Flowmetering
Straight Pipe-run Arrangements
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 8
Positive Displacement Flowmeters
Page 1 of 3
Section 8 IE250-IH
Liquid & Gas Flowmetering
Section 8
Rotary Inferential Flowmeters
Turbine Flowmeter Vortex Meter
Basis of Operation
Turbine meters have rotor-mounted blades that rotate when a fluid pushes against them
The rotational speed of the turbine is proportional to the mean velocity of the fluid
Selection and Sizing
Sized by volumetric flow rate The main factor affecting the meter is viscosity Turbine meters are specified with minimum and maximum linear flow
rates
Page 2 of 3
Section 8 IE250-IH
Liquid & Gas Flow Metering
K-Factor
The K-factor is the number of pulses per unit volume.
Typical Calibration Curve
Page 3 of 3
Section 8 IE250-IH
Liquid & Gas Flow Metering
Advantages
High accuracy/repeatability/ rangeability for a defined viscosity and measuring range
Fairly high temperature range Very high pressure capability: 600 bar Measurement of non-conductive liquids Capability of heating measuring device Suitable for very low flow rates
Disadvantages
Not suitable for high viscosity fluids Viscosity must be known 10D upstream and 5D downstream of straight pipe is required Not effective with swirling fluids Only used for clean liquids and gases Pipe system must not vibrate Specifications critical for measuring range, and viscosity
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 9
Ultrasonic Flowmeters
Page 1 of 5
Section 9 IE250-IH
Liquid & Gas Flowmetering
Section 9
Electromagnetic Flowmeters
Electromagnetic Flowmeters BASIS OF OPERATION
Electromagnetic flowmeters use Faraday’s law to sense liquid velocity Faraday’s law:
• moving a conductive material at right angles through a magnetic field induces a voltage proportional to the velocity of the conductive material.
Conductive material is the liquid
Electromagnetic Meter
Page 2 of 5
Section 9 IE250-IH
Liquid & Gas Flowmetering
Page 3 of 5
Section 9 IE250-IH
Liquid & Gas Flowmetering
Magnetic Flowmeters
Accurate, and have a linear relationship between flow and output voltage
High accuracy units to 0.2%
Selection and Sizing
Two main requirements are maximum and minimum velocity
Downsizing the meter increases flow-rate (velocity) through the meter
Page 4 of 5
Section 9 IE250-IH
Liquid & Gas Flowmetering
Application Velocity range, m/s
Normal service 0.6 - 12
Abrasive slurries 3.0 – 5.0
Non-abrasive slurries 1.5 – 7.5
Selection and Sizing - Liners
Meter can be lined with insulating material to prevent damage to electrodes
Liner is chosen for resistance to: • Chemical corrosion • Erosion • Abrasion • Pressure • Temperature
Installation Techniques
Pipeline must be full • Sufficient back pressure must be maintained
5 diameters of straight pipe upstream 3 diameters of straight pipe downstream Earthing is another important aspect
Advantages
No restrictions to flow • No pressure loss
No moving parts Good resistance to corrosion Independent of viscosity, density, pressure and turbulence Good accuracy Bi-directional Large range of flow rates/diameters
Page 5 of 5
Section 9 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
Expensive
Limited to conductive liquids
Minimum conductivity about 5 micro Siemens /cm
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 10
Mass Flowmeters and Selection
Page 1 of 4
Section 10 IE250-IH
Liquid & Gas Flowmetering
Section 10
Positive Displacement Flowmeters
Positive Displacement Flowmeters
Meters measured flow rate by repeatedly passing a known quantity of fluid from the high to low pressure side of the device in the pipe
The number of times the known quantity is passed gives information about the totalised flow
The rate at which it passes is the volumetric flow rate
Rotary Vane
Spring loaded vanes slide in and out of a channel in a rotor. They make constant contact with the eccentric cylinder wall. As rotor turns, a known volume of fluid is trapped between the vanes
and the outer wall. Flow rate is based on volume per revolution.
Rotating Vane Meter
Page 2 of 4
Section 10 IE250-IH
Liquid & Gas Flowmetering
Typical Applications
This type of meter is used extensively in the petroleum industry for such
liquids as gasoline and crude oil metering
Custody transfer
Advantages
High accuracy of 0.2% Suitable for high temperature service, up to 180oC Pressures up to 7MPa
Disadvantages
Clean liquids Head loss Expensive High Wear
Lobed Impeller
his type of meter uses two lobed impellers The impellers are meshed to rotate in opposite directions within the
inclosure A known volume of fluid is transferred for each revolution
Rotating Lobe Meter
Page 3 of 4
Section 10 IE250-IH
Liquid & Gas Flowmetering
Advantages
High operating pressures, up to 8 MPa High temperatures, up to 200oC.
Disadvantages
Clean liquids Head loss Expensive High wear
Oval Gear Meters
Two oval gears are intermeshed, trapping fluid between themselves and the outer walls of the device
Fluid pressure causes gears to rotate Revolution count determines volume of fluid moving through the device
Positive Displacement Meter
Advantages
High accuracy of 0.25% High operating pressures, up to 10MPa High temperatures, up to 300oC Wide range of materials for construction
Page 4 of 4
Section 10 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
Pulsations caused by alternate drive action
Application Limitations
Positive displacement meters can be damaged by overspeeding Primarily suited for clean lubricating and non-abrasive applications Filters/air eliminators required Limitations on operating temperature Meter is driven by the flow
Advantages
Can measure non-conductive liquids Very high accuracy Unaffected by viscosity High turndown of up to 10:1 Can be used in a pump dosing mode
Disadvantages
Clean fluids only, limited life due to wear Some irrecoverable pressure loss Requires viscous fluid Limited operating range Mechanical failure likely to cause blockage in pipe Cost
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 11
Miscellaneous Devices
Page 1 of 3
Section 11 IE250-IH
Liquid & Gas Flowmetering
Section 11
Ultrasonic Flowmeters
Ultrasonic Flow Measurement
Two types of ultrasonic flow measurement: • Transit time measurement • Doppler effect
Transit Time
The transit time flowmeter device sends pulses of ultrasonic energy diagonally across the pipe.
Transit time is measured from when the transmitter sends the pulse to when the receiver detects the pulse.
Transit Time Measurement
Page 2 of 3
Section 11 IE250-IH
Liquid & Gas Flowmetering
Installation Techniques
Fitted section of pipe Clamp on Transducers installed in-situ
Application Limitations
Clamp-on designs limited due to differing mediums in which ultrasonics pass through
Sound-conductive path is required between transducer and process fluid inside the pipe
Couplings are available but expensive
Doppler Effect
Relies on objects with varying density in flowstream to return ultrasonic energy
Using Doppler effect meter, a beam of ultrasonic energy is transmitted diagonally through the pipe
This energy is reflected back in varying amounts due to particles in the stream with different densities
Page 3 of 3
Section 11 IE250-IH
Liquid & Gas Flowmetering
Application Limitations
The Doppler flowmeter relies on reflections from particles/bubbles in the flowstream
It requires solids or bubbles in flow
Advantages
Suitable for large diameter pipes No obstructions, no pressure loss No moving parts, long operating life Fast response Installed on existing installations Not affected by liquid properties
Disadvantages
Accuracy is dependent on flow profile Fluid must be acoustically transparent
Application Limitations
Turbulence or swirling in the process fluid can affect the ultrasonic signals.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 12
Flowmeter Calibration
Page 1 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Section 12
Mass Flowmeters
Mass Flowmeters
Mass flow measurement gives a more accurate account of fluids
Mass flow measurement is not affected by density, pressure and temperature
The Coriolis Effect
Based on Newtons Second Law of Motion.
Force = Mass x Acceleration.
Manipulation of the formula allows us to determine the mass of fluid, for a known force and acceleration.
The Coriolis effect causes a retarding force on a rotating section of pipe
when flow is moving outward.
This conversely produces an advance on the section of pipe for flow moving toward the axis of rotation.
Page 2 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Application of Coriolis Force to a Flowmeter
Coriolis Flowmeter Construction
Page 3 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Straight Through Flowmeter
A development to the looped type Coriolis meter is the straight through
pipe version This has an advantage of lower pressure loss Rotational movement is provided by vibrating the pipes Coriolis force develops in the pipes Pipes are vibrated at their resonant frequencies Sensors are used to detect the movement of the pipe
Basic Principle of ‘Straight Through’ pipe
Page 4 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Advantages
Direct, in-line mass flow measurement Independent of temperature, pressure, density and temperature
information Sensor capable of transmitting mass flow, density and temperature
information High density capability Conductivity Independent Suitable for hydrocarbon measurements Suitable for density measurement
Disadvantages
Cost Affected by vibration Installation costs
Application Limitations
High temperature Vibration Amount of gas in liquid Restricted to low flow rates Limited to pipe sizes up to 150 mm
Coriolis Mass Flowmeter
Page 5 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Net Oil Computing
The NOC determines water cut by comparing the measured emulsion density to standardized reference densities of free oil and water.
Density is inversely proportional to the square of the flow tube
frequency.
The NOC combines flow and density outputs from the transmitter to compute and display the emulsion volume in cubic meters or U.S. barrels.
Page 6 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
The net oil application of the Coriolis meter employs a computer, which stores the manually entered oil and water base densities.
Because different wells may be flowing consecutively through the same
meter, there is a facility to storethe individual base densitiesof several different wells which may exhibit different base density values for their components.
Thermal Mass Flowmeters
The two main types of thermal mass flow measuring devices are: • Thermal Anemometer • Temperature rise flowmeter
Page 7 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Advantages
Fast response times, <0.5 ms
Disadvantages
Require 10D of straight pipe upstream
Have similar limitations to pitot tubes
Temperature Rise Flowmeter - Insertion Type
Work on the principle of heating the flowstream.
Heating flowstream at one point, allows measurement of temperature both upstream and downstream of heating point.
Principle of Temperature Rise Method
Page 8 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Disadvantages
Suitable for low gas flows only Subject to erosion and corrosion More tapping points, increased chances of leakage
Temperature Rise Flowmeter - External Type
Newly developed methods for insertion type sensing has seen heating and sensing elements moved to the outside of the pipe
This overcomes problems with tapping points
Thermal Flowmeter with External Elements and Heater
Page 9 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Bypass Type Thermal Mass Flowmeter
Advantages
Non-contact, non intrusive sensing No obstruction to flow Reduced Maintenance
Disadvantages
Suitable for low gas flows only Subject to erosion and corrosion
Flow Meter Remains Full
Page 10 of 10
Section 12 IE250-IH
Liquid & Gas Flowmetering
Parallel Arrangement
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 13
Flowmeter Installation Guidance
Page 1 of 3
Section 13 IE250-IH
Liquid & Gas Flowmetering
Section 13
Miscellaneous Devices Cross Correlation Techniques
Figure shows the operating principle. At least two transducers are positioned at points a known distance apart which are then used to determine the time taken for the passage of some naturally occurring event in the flow such as turbulent eddies or particulates.
The correlation meter can be applied in two phase flow conditions. If the phases are tagged with, for example, different radioactive tracers, then phase velocities, phase slip and bulk mean velocity can be determined. Successful results have been reported at oil wellhead installations, where water, oil and gas flow as a complex mixture.
Page 2 of 3
Section 13 IE250-IH
Liquid & Gas Flowmetering
Tracer Techniques
These techniques rely on adding a marker or tracer at one point in the flow and detecting the presence of the tracer at a second point, a known distance downstream. For liquids, tracers include salt solutions, dyes or radioactive substances. For gases, the radio-active tracer is the most commonly used.
The main advantages: They are (virtually) non-invasive. Associated equipment is rugged and portable. Readings can be taken where plant access is difficult. The in-situ calibration of meters is thus easy to accomplish.
Liquid and Gas Flow Metering
The main disadvantages: The methods are not appropriate for continuous flowrate measurements. In most cases the methods do not give an instant result. Subsequent
laboratory data analysis is required. The criterion of good mixing must be met. The tracer method injects a suitable tracer for a short period of time at
the upstream section and records the dilution effect at a section a known distance downstream.
An approximation of the mean flow velocity can be obtained by measuring the time for the tracer to travel the distance between the two sections and for its concentration to reach a maximum. By measuring the time interval of the profile centroids, the flowrate can be obtained from: Q = flow area x {distance between sample points } / {time between profile centroids }
Tracer methods are applicable to a very broad range of metering problems in both industrial and research environments and instances where they can be used include:
On-line calibration of installed flowmeters.
Measurement of open channel flows.
Investigations of systems and plants not provided with installed flowmeters.
Diagnosis of plant malfunction.
Page 3 of 3
Section 13 IE250-IH
Liquid & Gas Flowmetering
Weighing Techniques
Only applicable to batch type processes and not for continuous processes. In industrial plant the weighing system can replace the flowmeter
completely and can achieve a cost effective alternative to mass meters. For the non-continuous metering of mixtures, solids and other difficult
fluids, commercially available load cell systems are standard practice.
Velocity Area Integration Methods
Involves the measurement of flow velocity at a number of points on one cross section of a pipe.
Mean velocity and hence the flowrate can be calculated using integration.
Velocity measurements can be made by either an array of individual devices or by one device, such as a Pitot tube, annubar or a laser anemometer with a traversing mechanism.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 14
Flowmeter Costs and Flowmeter Selection
Page 1 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Section 14
Flowmeter Calibration A. Calibrators for Liquid Flowmeters
One characteristic of a liquid is that it can usually be contained in an open vessel, although if the liquid is volatile or hazardous suitable precautions have to be taken.
Calibration standards are usually of the 'bucket and stopwatch' type with the bucket either being weighed or the volume known.
Liquid and Gas Flow Metering
‘Standing start and stop’ method Flow through the meter is accelerated as quickly as possible from rest to the full test flowrate. At the end of the test the flow is rapidly stopped.
‘Flying start and finish’ method Requires some sort of diverter in conjunction with a sump or reservoir into which the liquid flows and then is diverted into the measuring vessel for the appropriate time.
Page 2 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
A flowmeter can be calibrated gravimetrically by statically weighing the quantity of liquid collected in a weighing vessel.
The vessel is weighed empty and then full and the difference in readings, corrected for the effect of air buoyancy provides the mass of liquid collected. If a volume flowmeter is to be calibrated this mass is divided by the density of the liquid at the flowmeter.
Page 3 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering Pipe Provers
To calibrate meters on line, a pipe prover can be used in Figure 6. A length of pipe is fitted with switches so that the volume between the switches is known. If a displacer ( or pig ) is introduced to the flow, the time it takes to travel between the switches will give a measure of the flowrate.
These devices are used extensively to measure all types of high value fluid from LPG to high viscosity crude oil and are produced in all sizes from 3-36 inches diameters.
Unidirectional sphere prover Displacer only travels in one direction along the pipe. Displacer is an elastomer (neoprene, polyurethane, etc) sphere which
is usually hollow. Centre is filled with liquid and inflated until it is larger than the pipe bore to make a good seal to the pipe wall.
The pipe is normally steel with internal surface usually coated to provide a smooth low friction lining and to protect against corrosion.
At each end of the calibrated length of pipe a detector switch is located through the pipe-wall which triggers the switch when the sphere passes under it.
At the end of this prover is the sphere handling valve. This arrangement is designed to hold the sphere. When required the sphere can be launched into the flow and carried round the loop. At the end of the loop the sphere is captured and returned to the launch position ready for another run.
Page 4 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering Bi-directional sphere prover
To reduce the pipe length, the bi-directional prover was developed. Similar in layout to the previous type, the flow can circulate around the
loop in both directions. A four-way valve changes the flow path without breaking the flow.
Piston provers For difficult fluids which may destroy lining, or leak past the
conventional sphere, piston provers have been produced. In this case the calibrated pipe is a smooth pipe of stainless steel or
plated carbon steel. The displacer is a piston with multiple seals. Switches can be conventional plungers or non-contacting type. These provers are bi-directional and controlled using a four-way valve.
Small volume (or compact provers)
These normally have a volume about one-tenth of a conventional design. They are normally piston provers with the detectors mounted external to
the pipe to ensure a high resolution for a small distance travelled.
Page 5 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
B. Calibrators for Gas Flowmeters
Calibration method is determined by the meter type, the ranges of flow and flow conditions, pressure and the accuracy of calibration required.
A primary standard method is one in which reference flowrate is determined by measurements of mass, length, temperature and time.
A secondary standard method is one in which reference flowrate is determined using a flowmeter which has been calibrated by a primary method.
Liquid and Gas Flow Metering Displacement Methods
A number of devices are used for gas calibration based on the principles of the pipe prover. The biggest drawback of any prover system is the friction at the displacer/pipe seal. Mercury seal provers use a very light displacer, with a mercury ring acting as the seal sliding in a glass pipe.
Some high pressure, more conventional, provers exist where the density/pressure of the gas keep seal friction below critical levels.
Soap film burettes are a common calibration device. This method is used to measure small gas flows within the range 10-7 to 10-4 m3/s at conditions close to ambient. What is created is a pipe prover with the displacer formed by a soap film or bubble.
To calibrate a flowmeter the system is set up as shown in Figure 10. Gas flow from the meter on test passes through a vertically mounted burette. As the gas enters the burette a soap film is formed across the tube and travels up the tube at the same velocity as the gas. By measuring the time of traverse of the soap film between graduations at either end of this burette the rate of flow of the gas may be obtained.
Page 6 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering Critical Flow Venturi-nozzle
If the pressure drop between the inlet and the throat of a nozzle or restriction is increased until sonic velocity is reached at the throat, then for a given value of the upstream pressure and temperature, the mass flowrate through the nozzle will be constant. The expression for the mass flowrate m of the gas is:
m = Cd C* At P0 / ( RT0 )1/2
Page 7 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
The mass flowrate under sonic conditions is independent of downstream pressure and temperature and dependent only on the geometry of the nozzle, the properties of the gas, and the upstream pressure and temperature.
This feature makes the device particularly suitable for calibrating meters. Internationally agreed standard flowmeter.
A standard sonic Venturi is shown in Figure 12.
Page 8 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
On-site Flowmeter Calibration Tracer methods
For the transit time method a pulse of tracer fluid is injected into the main flow stream, and the time taken for the tracer to pass between two detection points is noted. If the volume of pipe between the detectors is known the volumetric flow of the flow can be determined.
For the dilution method a tracer fluid which is detectable in low concentrations, is injected into the flow (Figure 15) at a known flow rate q m3/s. The mainstream flow is then sampled at a distance downstream of the injection point far enough to have allowed homogeneous mixing to have taken place, and the concentration, C, of the tracer is measured. The flowrate can be derived from:
Q = q / C Flowrate can be determined to within 0.5 per cent.
Page 9 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Velocity Traversing Methods
Flowrate is estimated by measuring a number of point velocities at discrete positions in a cross-section of the flow, and then integrating these over the flow cross-section (Figure 16). The most commonly used instruments are anemometers, insertion meters and Pitot tubes.
Main disadvantages of these methods are that they are time consuming, and difficulties are encountered with unsteady flows. For gas velocities in the range 0.3 to 3.0 m/s uncertainties of 4 per cent are attainable using vane anemometers and for velocities in the range 6-120 m/s 2 % can be achieved using Pitot tubes.
Page 10 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Clamp on Ultrasonic Meters
Clamp on ultrasonic meters can also be used for in-situ calibrations but many factors have to be considered such as flow profile, pipe material and internal condition and fluid properties.
Accuracies of no better than 2 - 10% can be assumed.
The Importance of Calibration Fluid
It is important, especially for liquids, to calibrate in the same fluid as that which the meter will normally see.
For liquid meters, especially those required to meter hydrocarbons, the choice of calibration fluid is particularly important.
Figure 17 shows results for large turbine meter for water and three petroleum products of different viscosities. It is important therefore to calibrate these meters using the actual working liquid and for this reason, turbine meters for crude oil are often calibrated on site using a dedicated pipe prover and the actual operating liquid.
Page 11 of 11
Section 14 IE250-IH
Liquid & Gas Flowmetering
Calibration Conditions
The pressure and temperature at which a flowmeter is to operate are important factors, particularly for gas meters.
Pressure and temperature not only affect the dimensions such as the throat diameter of a nozzle or the clearances in a positive displacement meter, but in the case of gas flow can have a significant effect on the gas density and viscosity as well.
To ensure that the velocity profile is fully developed and symmetrical it is essential that the calibration system gives adequate straight pipe upstream of the test meter.
Calibration Accuracy
Liquid flowmeter calibration facilities should be able to measure flowrates to uncertainty levels between 0.5 and 0.05 per cent depending upon the size, cost and complexity of the system.
Calibration systems for gas flowmeters should be able to measure flowrate to uncertainty levels of 0.5 per cent.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 15
Introduction to Multiphase Flow Measurement
Page 1 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Section 15
Flowmeter Installation Guidance
Liquid and Gas Flow Metering Most flowmeters are designed to operate in ideal conditions. In practice the meter is likely to generate a measurement error. Common sources of this "installation error" include:
Upstream and downstream disturbances such as bends or valves Flow pulsations Acoustic noise sources and vibration Particles or bubbles in the flow
Flow Disturbances & Other Sources of Error
A disturbed region is generated downstream of pipework fixtures such as bends or valves.
Most flowmeters are intended for use in undisturbed (fully developed) flow, with a large length of straight pipe upstream of the meter. However, in reality, it is rarely possible to achieve this and most flowmeters are exposed to disturbed flow.
Classification of Flow Disturbances Pipework fixtures disturb the flow by:
Changing the distribution of flow in the pipe (distortion of the axial velocity profile)
Causing the flow in the pipe to swirl Changing the turbulence of the flow in the pipe
Page 2 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Distortion of the Axial Velocity Profile
The flow in a pipe is fastest in the centre and slowest at the walls. This produces a fully developed velocity profile, as shown in Figure 1.
If, for example, the fluid passes through a valve, the flow will be skewed to one side of the pipe generating higher velocities near the wall. Other disturbances may act to increase the velocity at the pipe centre and decrease it near the walls creating a peaked velocity profile.
Liquid and Gas Flow Metering Swirl
In fully developed flow all of the fluid travels parallel to the pipe walls. Some pipework fixtures can impart rotational movement on the flow, generally referred to as swirl.
Some disturbances generate single vortex swirl, others double,
triple or even quadruple swirl (see Figure 2).
Page 3 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Generation of Turbulence
In nearly all cases of interest to Engineers the flow in pipes includes random turbulent fluctuations. In fully developed flow these turbulent fluctuations are usually less than about 3% of the local mean fluid velocity. Passing fluid through pipework fixtures effectively stirs up the flow, usually causing increased turbulence.
Downstream Flow Conditions
Standards and manufacturers recommendations usually specify only a short length of straight pipe downstream of the meter, as being necessary.
This is not universally correct, some types of meter can be grossly affected by swirl or velocity profile distortion introduced as much as 3D downstream of the meter.
Generation and Decay of Flow Disturbances General Rules of Thumb
In general disturbing elements that are in the same plane generate peaked, flattened or skewed velocity profiles. Examples include single bends, S-bends, U-bends, expansions and contractions (see Figure 3).
The most typical situation in which swirl occurs is two 90° bends in planes at right angles to each other. Several severe swirl producing pipe configurations are shown in Figure 4.
Page 4 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Page 5 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
The following rules of thumb can be applied:
Distortion of axial velocity profiles generally decays to near zero in about 20 to 30 pipe diameters (20 - 30D)
Single vortex swirl can persist for more than 100D. Double and multiple
vortex swirl decays within 20D
Turbulence generally decays to fully developed levels in less than 20D
Pipe Contractions and Expansions
Contractions produce an initially flattened velocity profile. Further downstream this will become peaked, before finally becoming fully developed.
Expansions produce the opposite effect - peaked, flattened then fully developed.
Pipework Mismatches, Weld Root Intrusions and Gaskets
Mismatches of pipework can often occur at flanges creating a step change in pipe diameter and will produce flattened or peaked profiles.
Misaligned flanges will skew the velocity profile. Weld intrusions into the pipe bore can significantly alter the flow.
Single Bends and Elbows
Flow passing through a single bend is forced to the outside of the bend producing an asymmetrical velocity profile at the bend outlet. The flow also moves round the walls of the pipe from the outside towards the inside generating symmetrical double vortex swirl.
Double Bends
S-bends produce a flattened profile and quadruple vortex swirl, both of which tend to decay quite quickly.
Out-of-plane double bends generate a flattened velocity profile and single vortex swirl. The closer the two bends, the greater this swirl will be. The swirl generated by double out-of-plane bends can persist for more than 100D.
Page 6 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Valves
Gate valves, sluice valves and ball valves skew the velocity profile when partially closed. Butterfly valves always disturb the flow, even when fully open.
Many non-return valves have a flap that hangs free in the flow. The disturbance generated by this arrangement depends on the angle of the flap and hence the flow rate.
Fiscal flowmetering installations in the oil industry generally use ball valves with machined bores that present no disturbance to the flow when fully open.
Other Installation Disturbances
Measurement errors generated by flow disturbances can be in excess of 50% for some meters. Flowmeters installed in disturbed flow therefore tend to provide realistic looking readings. This can make it difficult to spot that the meter is in error. Other potential sources of installation error include:
• Low or High Temperatures and Pressures • Noise and Flow Pulsations • Pipe Roughness, Corrosion and Deposition • Particulates, Bubbles, Droplets • Cavitation Flashing and Multiphase Flows
Installation Effects on Specific Meters Orifice Plates, Nozzles and Venturis
Guidance on installation is given in IS05167. Installation effects for differential pressure flowmeters are often given in terms of the percentage shift in the discharge coefficient, C.
A 1% shift in C will result in a flow measurement error of almost exactly 1 %.
Flow disturbances can result in errors of 10% or more. In general, orifice plates are most affected, then nozzles, and Venturis are least affected.
Most flow disturbances produce a positive error (over-reading) except for single vortex swirl
Low ratio meters are generally least affected by flow disturbances except for single vortex swirl.
Single vortex swirl causes a positive error in Venturis. For orifice plates and nozzles single vortex swirl causes a negative error
in low ratio meters and a positive error in high ratio meters.
Page 7 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
As single vortex swirl can persist for more than 100D this is often considered to be the worst kind of flow disturbance.
Roughness effects, especially within the meter itself, can be significant. Erosion, corrosion and the build up of grease or sealant on the upstream face of an orifice plate may be an issue.
Erosion of the sharp edge of the orifice of an orifice plate can cause large errors.
Orifice plates and nozzles with corner tappings are most affected, then flange tappings, then D-D/2 tappings.
A large pressure difference across an orifice plate can cause it to bow or buckle, generating an error. Also large pressure differences may produce cavitation.
Orifice plates can be unintentionally installed backwards. This can result in measurement errors of between -10% to -20% depending on the plate.geometry.
Liquid droplets and solid particles in the flow will produce positive errors, increasing with droplet/particle concentration and density to +50% or more.
Electromagnetic Flowmeters
Electromagnetic flowmeters are usually provided with manufacturer's recommendations for installation.
Different designs of flowmeter have different characteristics and further
guidance is given in ISO 6817 In general electromagnetic flowmeters are relatively unaffected by
flow disturbances and a straight length of about 10D upstream is usually sufficient to keep the error caused by a bend or elbow to less than 1%.
Electromagnetic flowmeters are most sensitive to changes in velocity profile near their electrodes. This makes the orientation of the meter important. A meter installed close to a bend with its electrode in the plane of the bend will respond in a different manner to a meter with its electrodes perpendicular to the plane of the bend.
Swirl has little effect on electromagnetic meters. Meters with large electrodes, multiple electrodes and strong magnetic
fields are generally less affected by flow disturbances. Fouling of the electrodes can cause problems in some fluids. Electromagnetic flowmeters are often installed with their electrodes in
the horizontal plane to avoid contact with bubbles at the top of the pipe or particulates in the bottom.
Page 8 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Ultrasonic Meters
The response of ultrasonic flowmeters is dependent on the design and configuration of the meter. Figure 8 shows the response of three different flowmeters downstream of a single bend.
Manufacturers are likely to provide information on installation requirements.
The sensitivity of ultrasonic flowmeters to flow disturbances varies with the design of the meter. Single path meters can be in error by more than 10% if installed close to a bend.
In general, the more ultrasonic paths, the less sensitive the meter will be to flow disturbances.
Orientation of meter is important. The response of a meter to an asymmetrical flow disturbance will vary depending on whether its paths are horizontal, vertical or somewhere in-between.
As a rough guide, single path meters may need 30-40D of straight pipe downstream of a fixture, twin path meters 15-20D and only multipath meters may be satisfactory with much less.
When used in gas, ultrasonic flowmeters can be affected by acoustic noise, often generated by flow conditioners, valves or other fixtures.
The accuracy of clamp-on meters can suffer if the pipe onto which they are clamped is rough or ovoid. It is essential that the ultrasonic transducers are properly aligned and to ensure that the contact grease maintains a good interface with the transducers.
The transducer ports should be installed horizontally to prevent a build up of particulates or bubbles. Cavitation may also be an issue in these ports for low pressure, high flow rate applications.
Particulates, droplets and bubbles can affect ultrasonic flowmeters either by dissipating the ultrasonic pulses or distorting the velocity profile in the metering spool.
Turbine meters
The response of axial turbine meters to flow disturbances is very dependent on the design of the meter.
In general turbine meters are relatively insensitive to skewed velocity profiles and multiple vortex swirl. Peaked and flattened profiles may have a limited effect, but single vortex swirl is likely to cause errors of the order of 10%
Intuitively, if the direction of the swirl matches the rotation of the rotor of the meter one would expect an over-reading.
Swirl generated downstream of turbine meters can also induce errors. Audible noise and flow pulsations affect some meters, usually causing an
over- reading.
Page 9 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Vortex meters
Vortex meters are affected by all flow disturbances and can give positive or negative errors of up to 3%, if sufficient length of straight pipe is not provided upstream of the meter.
For most pipe fittings an upstream straight pipe length of between 10D and 30D is required.
Where swirling flow is likely to be produced, up to 70D may be necessary.
Vibration and pulsations in the flow may affect vortex shedding and the counting mechanism. An effect has been observed in which vortex meters "lock on" to the pulsation frequency.
Variable area meters
Variable area meters are known to be less sensitive to swirl or asymmetry than the majority of flowmeters
Upstream pipe configuration is relatively unimportant, but control valves should be placed downstream of the meter
Positive Displacement Flowmeters
Displacement meters are very tolerant of both upstream and downstream flow conditions and are unaffected by swirl or asymmetry.
Coriolis Flowmeters
Do not require a well developed flow profile. It is vital to avoid the vibration of adjacent pipework.
Thermal Mass Flowmeters
Errors in excess of 10% are likely for a probe type meter close to a bend. These meters are not particularly sensitive to vibration, but the probe
type meters should be adequately fixed to the pipe wall to prevent resonance.
Remedial Action Calibration of the Metering System
If the installation error can be measured or calculated, it can be accounted for and hence eliminated. Instead of calibrating the
Page 10 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
flowmeter on its own, it might be better to calibrate the meter complete with the upstream and downstream pipework.
In-situ Calibration Techniques
The measurements of an installed flowmeter may be compared against those of another meter in the same flow. This has the advantage that two different types of meter can be selected which have different sensitivities to flow disturbances. The disadvantages of this approach are additional cost and meters may interfere with each other.
Flow Conditioners and Flow Straighteners
These are often positioned between a flow disturbance and a flowmeter in order to reduce the length of straight pipe required to ensure that the flow entering the flowmeter is acceptable.
Disadvantage with these is that they increase the pressure loss through
the metering system and can be fouled or blocked.
Types of Straightener
Most popular is the tube bundle. Figure 10. Length to diameter ratio of the tubes is usually > 10. Increasing the
length increases the pressure drop across the straightener. Other designs include the Etoile and AMCA, both of which are most
commonly used in gas.
Page 11 of 11
Section 15 IE250-IH
Liquid & Gas Flowmetering
Types of Conditioner
These generally comprise a perforated plate, sometimes with a flow straightening element downstream. Flow conditioners generally improve the axial velocity profile as well as removing swirl.
An NEL Spearman flow conditioner in Figure 11. Other designs include the Sprenkle, Zanker, Mitsubishi, Gallagher and K-Lab Laws conditioners.
Zanker and NEL designs are the easiest type to install and can be slid between two flanges without disturbing any other fittings.
Flow conditioners are not recommended for use with wet gas ( but Emerson 4-hole orifice works well).
Conclusions
Installation errors can be caused by flow disturbances or other aspects Flow disturbances are generated by bends, valves etc. Different flowmeter designs respond in different ways to installation
effects Remedial actions include:
Selection of an alternative meter Redesign of pipework surrounding the meter Recalibration of the metering system to account for the error Use of a flow straightener or conditioner
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 16
Basic Concepts of Multiphase Flow and Multiphase Flowmeter
Page 1 of 2
Section 16 IE250-IH
Liquid & Gas Flowmetering
Section 16
Flowmeter Costs and Flowmeter Selection
Liquid and Gas Flow Metering
Best flowmeter might be the most reliable meter at the lowest cost when giving the user the required performance, but fluid properties and ambient effects need close consideration.
Cost includes the initial purchase of the flowmeter, installation, running, calibration and maintenance costs.
A recent survey showed about 50% of failures were due to poor application, 43% had installation defects and only 7% were due to equipment or design defects.
Initial Considerations
Sometimes, the plant operator may only wish to know whether the fluid in the pipework network is moving slowly, quickly or not at all. Under these circumstances, a flow indicator is needed, at a fraction of the cost of most flowmeters. If alarm limits for high or low flow are required, then indicators can be fitted with a simple microswitch to sound the required alarm.
If an indication of flowrate to within 10% is needed, it may still be unnecessary to purchase a flowmeter. As an example, many installations have changes of section or bends somewhere in the system. By inserting pressure tappings at selected points, a simple differential pressure transmitter would then employ the pipework as a crude Venturi or elbow meter.
If better accuracy is required or the signal is used to control the process, then flowmeter selection needs to be carried out.
Page 2 of 2
Section 16 IE250-IH
Liquid & Gas Flowmetering
Initial Considerations
The user must know: Physical and chemical fluid properties Range of flowrates expected or required Fluid temperature and pressure ranges to be covered Ambient temperature range expected Duration of operation (continuous or intermittent) Location of meter or metering station Accessibility for maintenance Required accuracy Resources available
Flowmeter Selection Procedure
There are many factors to be considered: Installation considerations Performance considerations Fluid property considerations Environmental considerations Economic considerations
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 17
Current Main Suppliers of Multiphase Flowmeters
Page 1 of 3
Section 17 IE250-IH
Liquid & Gas Flowmetering
Section 17
Quality Assurance and Standards
Calibration
Calibration is a set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring system and the corresponding values realised by standards.
The establishment of the relationship can be the production of an error figure or the definition of corrections. Another word is 'Proving'. Proving is normally meant to be a calibration where the 'relationship' is a proof of conformance to a specification.
Traceability
The property of the result of a measurement whereby it can be related to national or international standards, through an unbroken chain of comparisons all having stated uncertainties.
This ensures that that each standard or measure used for calibration purposes has itself been compared against a standard of higher quality up to the level at which the higher quality instrument is the accepted National Standard.
Mass
The ultimate primary standard of mass is the international prototype of the kilogram, a solid cylinder of platinum- iridium preserved at the International Bureau of Weights and Measures at Sevres, Paris.
All standards of mass in use in the UK are derived from the secondary platinum-iridium copy (No 18) of the prototype kilogram, and kept at NPL.
Page 2 of 3
Section 17 IE250-IH
Liquid & Gas Flowmetering
Length
The UK standard is held by NPL and is based on the 633 nm red light helium-neon lasers stabilised by saturated absorption by iodine. When the operating conditions are specified in detail a reproducibility of wavelength of 1 part in 1011 can be achieved.
All advanced countries have established their own standards of length and inter-comparison ensures international agreement.
Time
The UK National Standard for the second, the interval of time, and for frequency is the long beam Caesium resonator developed at NPL.
Inter-comparison with other similar high quality standards ensures international agreement and definition of the measure of time.
Temperature
Temperature is defined by fixed physical state changes of specific elements or compounds.
Temperatures between the fixed points are defined by the resistance of platinum wire and its known change with temperature between the fixed points.
Flow Standards
A flow measurement standard is derived from and dependent on a combination of other more basic standards of mass, length, time, pressure and temperature. It may be either gravimetric or volumetric.
It is not usually a device which can be easily transferred from one location to another nor, because of its size and complexity, is it something which can be kept in a glass case.
Page 3 of 3
Section 17 IE250-IH
Liquid & Gas Flowmetering
National Measurement System (NMS)
Within every modern state there exists a National Measurement System. Without such a system internal and external trade and manufacture could not function.
It is the function of the National Measurement system to establish the measurement standards to which reference and working standards within the country are traceable and ensure these standards can be recognized internationally.
Accreditation
Accreditation is the process in which a third party inspects and approves a calibration or test laboratory to ensure it meets its stated capability for the measurements it offers.
Certification
This is the process by which a company, product or instrument is certified as complying with, or calibrated to, a specified standard by a third party.
This implies that the process or product has been inspected and deemed to meet the requirements of the relevant standard or specification.
Items carrying the TUV mark will have had the process of production certified.
Items CE marked indicates that the supplier confirms the item complies with the relevant directive(s).
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 18
Level Measurement
Page 1 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Section 18
Introduction to Multiphase Flow Measurement
Description of Multiphase Flows
Multiphase flow, in the hydrocarbon production industry, is concerned with the simultaneous flow of mixtures of oil, water and gas.
When attempting to meter such flows it is important to understand their nature, since this impacts on the most appropriate methods for metering and on the accuracy of metering.
Liquid and Gas Flow Metering
Multiphase flow of oil, water and gas potentially covers the full ranges of flowrates of all three phases. This will therefore include the range of gas volume fractions from 0% to 100% and water cuts from 0% to 100%.
Within these ranges, the characteristics of the flows can change dramatically, as a result of the relative velocities of the gas and liquid (and of the oil and water), the viscosity and the density differences.
Definitions Associated with Multiphase Flow
Continuous phase This is usually the predominant phase e.g in an oil flow in which separated water drops or gas bubbles are suspended. In exceptional cases, such as foams, however, the oil may account for only a few per cent of the flow, but still be the continuous phase in which the gas bubbles are suspended.
Page 2 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Velocity ratio The ratio of the mean gas velocity to the mean liquid velocity:
K = Ug / Ul = ( Mg / gAg ) / ( Ml / lAl) where Ag + Al = A the total cross-sectional area of the flow.
Quality Quality is the mass dryness fraction:
x = Mg / M
Void fraction
The void fraction is the fraction of the pipe area at a given cross-section which is occupied by the gas phase. This can vary considerably, e.g. in plug or slug flow but usually the variations are at such high frequencies that a time-averaged value can be used.
= Ag / A = ( x / g ) / { x / g + K ( 1 – x ) / l }
Density of the mixture If a density is required for use in flow equations for flowmeters in
multiphase flow then effective density e should be used where:
1 / e = { x / g + K( 1 – x ) / l } { x + ( 1 – x ) / K } = x2 / g +
( 1 – x )2 / ( 1 - )l
Note that for homogeneous flow, the velocity ratio K = 1, so that:
hom = m = 1 / { x / g + (1 – x ) / l }
Gas velocity The velocity of the gas phase in the pipe, Ug, can be determined from other variables as:
Ug = M { x / g + K(1 – x ) / l } / A
Homogeneous flow In reality it is difficult to define what constitutes homogeneous flow. In practice, however, the term is taken to mean a flow in which the two phases are uniformly and so well mixed that there is no relative slip between them, so that Ul = Ug = Uhom
Page 3 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Homogeneous velocity As defined above under homogeneous flow, the homogeneous velocity is:
Uhom = M { x / g + (1 – x ) / l } /A Slip
Slip is the difference between the mean velocities of the gas and the liquid phases:
UR = Ug - Ul
Superficial phase velocities
The superficial velocity is the velocity each phase would have if it flowed alone in the same pipe:
Ugs = Mg / g A = x M / g A
Uls = Ml / l A = ( 1 – x ) M / l A
Flow Patterns In Horizontal Two-Phase Flow
Two-phase flow patterns in a horizontal pipeline can be broadly categorised into four distinct flow regimes:
stratified, slug, annular and bubble flow
Between each of these flow regimes there are boundaries which may be
quite sharp (e.g. between stratified and slug flow) but are generally fairly indistinct transition regions.
Page 4 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering Stratified flow
Here the gas and liquid flow in distinct separate layers. The liquid occupies the lower part of the pipeline and the gas occupies the upper part.
Within this configuration there may be waves on the liquid surface and occasional splashing of liquid onto the upper walls, or entrainment of liquid into the gas phase.
The liquid-gas interface may be smooth, rough or wavy. Stratified flow with a wavy gas-liquid interface is sometimes described
as wavy flow.
Page 5 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering Slug flow
Slug flow is characterised by an intermittent behaviour. Observing a fixed point in the pipeline will show an alternation of high
and low liquid holdup. This corresponds to 'slugs' and a film region between the slugs.
The slug itself may contain a considerable fraction of entrained gas, which may vary along the length of a slug.
At higher liquid flowrates the flow may appear to be predominantly liquid phase with large asymmetric gas bubbles; this pattern is sometimes described as 'plug' flow.
Bubble flow
Bubble flow occurs at still higher liquid velocities where the entire pipe is continuously filled with liquid which contains entrained bubbles of gas.
Due to the effect of gravity, the bubbles will tend to collect in the upper part of the pipe.
There may be some variation in the fraction of gas bubbles with time, close to the transition points to slug or to annular flow.
Annular flow
Annular flow occurs when the liquid flows as a film on the pipe walls and the gas forms a core inside this liquid.
Again, under the effect of gravity, there will tend to be more liquid at the bottom of the pipe than the top.
A large fraction of the liquid phase may be entrained into the gas core and there may be waves or pulses of liquid particularly on the liquid layer at the bottom of the pipe.
Stratified / annular flow occurs when the gas velocity is sufficiently great to entrain liquid from a stratified flow, but insufficient to sustain a continuous liquid film.
Slug / annular flow occurs when the flow is intermittent as in the definition of slug flow, but with such a degree of gas flow in the slug body that there is a possibility of a continuous gas core.
Page 6 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Annular / slug flow is where the flow appears to be annular, but with a sufficient intermittent flow of liquid that there is not the possibility of a continuous gas core. This occurs with both greater liquid velocity and greater gas velocity than for slug/annular flow.
Bubble / slug flow occurs at higher gas velocities than bubble flow
where the greater volume of gas gives rise to agglomeration of bubbles with some degree of intermittency, but not to the extent of forming slug and film regions as seen in slug flow.
Flow Patterns in Vertical Two-Phase Flow
Two-phase flow patterns in a vertical pipe can be classified into: bubble, slug, churn and annular.
Between each of these flow regimes there are boundaries which are generally indistinct.
An additional flow pattern, wispy annular flow, can be observed at conditions of high mass flux, although this is unlikely to occur in multiphase hydrocarbon production systems.
Page 7 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Bubble Flow The liquid phase is continuous, and a dispersion of bubbles within the
liquid phase. Slug (or plug) flow At higher gas flowrates than for bubble flow, coalescence of the bubbles
occurs, and leads to the creation of characteristically bullet-shaped (Taylor) bubbles, which are separated by regions containing dispersions of smaller bubbles.
The liquid phase flows down the outside of the large bubbles in the form of a falling film, but the net flow of both liquid and gas is upwards.
Churn flow Increasing the flow velocity beyond that for slug flow leads to an
unsteady flow regime in which there is an oscillatory motion of the liquid upwards and downwards in the tube (hence the name churn flow).
Annular flow The liquid flows on the wall of the tube as a film, and the gas flows in
the centre. Usually some of the liquid phase is entrained as small droplets in the gas core.
Three-Phase Flow Pattern Effects in Vertical Flow
Unlike horizontal three-phase flows, there is no observed effect of the presence of oil and water phases on the flow patterns. This is because the mixing between oil and water maintains similar velocities of both phases, and gravity does not act to separate the oil and water.
The transitions between flow patterns are also unaffected by the water cut. In vertical flows, the transitions are dependent on momentum flux (product of density and superficial velocity squared). Hence the effects of liquid density changes between different water cuts is eliminated.
Multiphase Measurement Challenges
Pressure Drop Pressure drop is one of the most difficult 'simple' parameters of multiphase flow to make a meaningful average measurement. Empirical correlations have been produced to relate pressure gradient to other parameters of the flow, such as liquid and gas superficial velocities and the physical properties of the fluids.
Page 8 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
In multiphase metering, pressure drop measurement is most usually required for a Venturi. Two issues relate to these measurements:
Bleeding of the impulse lines between the Venturi and the pressure transmitter
Range required for the pressure transmitter However, this is not always possible in a multiphase flow where
fluctuations in the gas and liquid content of the flow will lead to ingress of gas into the impulse lines. This will be less of an issue the higher the operating pressure, since then the liquid and gas densities are closer than they would be at low operating pressure.
To minimise the impact of errors related to impulse lines it is desirable that the measured pressure difference is large compared to the static head between the Venturi tappings.
In slug flow it is possible that the maximum differential pressure through a Venturi (during a high liquid fraction portion of the flow) is up to 5 times the average pressure drop.
Therefore the Venturi differential pressure transmitter needs to have an operating range at least up to 5 times the expected maximum average pressure for the range of use of the meter. This may limit the rangeability of the meter in terms of maximum and minimum flowrates more strictly than may be the case in a single phase flow.
Mixing and Density Measurement
Measurement of average density in multiphase flow is usually achieved using a gamma densitometer which usually measure the attenuation of a gamma ray along a single cross-sectional chord.
Clearly it is required that this line density is equal to the area-averaged density of the flow, and by suitable time-averaging of line densities equal to the volume-averaged density of the flow. This will only be achieved in practice if the flow is homogenised.
Page 9 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
The gas and liquid are likely to be more evenly distributed across the cross-section in a vertical flow than in a horizontal flow, where gravity tends to separate the liquid to the lower part of the pipe.
In vertical flow, the line fraction density is likely to be more representative of the area-averaged density, and therefore a vertical flow orientation is used in most meters which use gamma densitometers.
The impact of mixing and of flow orientation on density measurement becomes less significant at higher operating pressure, where the gas and liquid densities converge.
Sampling and Random Errors Any individual multiphase flow measurement, e.g. pressure drop, density
etc., is meaningless on its own in a system where there is continuously fluctuating velocity and liquid fraction of the flow. An average measurement is required, and two factors will influence this:
A sufficient length of time to allow a representative sample of flow features (for example liquid slugs);
A sufficient number of individual measurements to reduce the confidence interval in the measured average to an acceptable level.
For laboratory evaluations of multiphase meters a test time of 5 to 10 minutes is usually sufficient to capture a representative sample of the flow.
In a field application, the input flow may not be as steady as in the laboratory; for example slugging in the flowline may be influenced by upstream topography so slug intervals at the meter may be several minutes. In this case a longer interval may be required.
If a measurement such as pressure drop is being made which may fluctuate over a 25:1 range during the test, then to achieve high confidence in the measured average of a few percent it would be necessary to take of the order of S103 measurement samples.
This implies a sampling frequency up to about 5 Hz, well within the capability of most types of sensor and data recording systems.
Page 10 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Flow Patterns Flow patterns can have a significant effect on multiphase flow measurement. In-line meters which do not mix the flow will need to know what the flow pattern is in order to interpret the measurements. If the flow pattern is different to that of the model the output may be incorrect.
Gamma attenuation methods will be influenced by flow patterns if the distribution of the phases along the gamma ray path through the fluid mixture is not representative of the cross-sectional distribution. This is most significant in horizontal flow, although even the measurement of gas fraction using a single energy gamma beam can be influenced by flow pattern in vertical flow.
A bigger problem with gamma densitometers is the effect of fluctuations in distribution on the measurement.
Performance of Single Phase Flowmeters in Multiphase Flows
Some types of single phase meters can be used quite successfully in multiphase flows; the best example is the Venturi. Providing that the correct density is measured and that the differential pressure is correctly sampled and averaged, the Venturi can be used to give a good mass flow measurement.
Liquid and Gas Flow Metering
Orifice meters are less suitable for use in multiphase conditions, due to a significant effect on differential pressure of liquid build-up on the orifice edges.
Positive displacement meters have been modified for use in multiphase flows. Mechanical devices in multiphase flows may be over-ranged and damaged by fluctuations in flowrate in slug flow. These meters should be avoided in single phase metering situations where there is a possibility of gas entering the liquid. They will always give measurements, until mechanical damage occurs.
Page 11 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Most other types of single phase meters function badly in multiphase flows with greater than about 6% gas in liquid or liquid in gas.
Turbine or Coriolis meters may tolerate a small percentage. Vortex meters tolerate virtually none. Ultrasonic meters can be used under some circumstances, but may fail
to give readings at all.
Page 12 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
Page 13 of 13
Section 18 IE250-IH
Liquid & Gas Flowmetering
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 19
Selection of Flowmeters
Page 1 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Section 19
Basic Concepts of Multiphase Flow and Multiphase Flowmeters
What is Multiphase Flow?
2 phase:
Oil + Gas
or
Oil + Water
or
Water + Gas
3 phase:
Oil + Water + Gas
What is a Multi Phase Flow Meter (MPFM)?
A device for measuring the individual oil, water and gas flow rates in a
multi-phase flow.
The total package of measurement devices for composition and velocity,
including possible conditioning unit, should be considered as an integral
part of the meter.
Page 2 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Multiphase Flow Regimes
For vertical upward multiphase flow, the flow regime that is observed under a
specific set of flow condition is dependent on
(i) The liquid superficial velocity
(ii) The gas superficial velocity
(iii) The mean gas void fraction
(iv) The size and shape
(v) The component transport properties including density, viscosity, and
surface tension of the flowing components
Impact of Multiphase Meter on Business
Page 3 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Two-phase Flowmap
Page 4 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
What is Superficial Gas velocity?
A derived velocity obtained by dividing the gas volume flow rate at actual
conditions by the cross sectional area of the conduit. In other words the
velocity of the gas if the gas was in the conduit without liquid.
What is Superficial Liquid Velocity?
A derived velocity obtained by dividing the liquid volume flow rate at actual
conditions by the cross sectional area of the conduit. In other words the
velocity of the liquid if the liquid was in the conduit without gas.
What is Gas Volume Fraction (GVF)?
The ratio of gas volume flow rate and the total fluid (oil, water and gas) flow
rate, both volume flow rates should be converted to the same pressure and
temperature. Expressed as a fraction or percentage.
What is Water Cut (WC)?
The ratio of the volume flow rate of water and the total liquid
volume flow rate, both volume flow rates should be converted to
the same pressure and temperature (generally at the standard
conditions).
It is generally expressed in a percentage.
Page 5 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Differential Pressure Devices (Venturi)
Page 6 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Cross Correlation
A cross-correlation flow meter measures the velocity of disturbances.
Composition Measurement
Single Energy Gamma Ray Absorption
In principle gamma ray absorption measurement works in the
0 - 100% watercut region and in the 0-100% GVF environment.
In a pipe, with inner diameter d, containing two phases the
absorption is described with:
3
1
).d](.exp[).()(i
iivm eeIeI
Page 7 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Im (e) is the measured count rate, Iv (e) is the count rate when the
pipe is evacuated and mi represents the linear absorption
coefficients for the two phases. Apart from the fractions (ai) also
the absorption coefficients (mi) are initially unknown. However, the
latter can be found in a calibration where the meter is subsequently
filled with the individual fluids or they can be entered in the
software after they have been determined offline.
Note that single energy gamma ray absorption concept as a
stand-alone measurement can only be applied in a two-phase
mixture.
Composition Measurement
Dual Energy Gamma Ray Absorption
The basics of the measurement are similar to the single
energy gamma ray absorption concept, but now two gamma of
energies e1 and e2 are used.
This measurement is applied in three phase oil, water and gas
mixture.
The use of radioactive sources requires proper licences, safety
procedures, and custodianship and, quite often, psychological
and emotional barriers have to be overcome as well. This
makes their use difficult or even impossible in some parts of
the world.
Page 8 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Commonly used sources are Am-241, Ba-133, Cs-137 and Gd-
153.
Composition Measurement
Dielectric (Electrical) Properties
Oil-continuous emulsions (water droplets in a continuous oil medium) are
non-conducting.
Water-continuous emulsions (oil droplets in a continuous water medium)
are conducting.
At the transition point going from oil-continuous to water-continuous the
leakage resistance across a capacitive sensor changes from large to small,
causing the sensor to be short- circuited. The measurement fails.
Cheap
Not full range
Igas(e2)
Ioil(e2)
Iwater(e2)
Iwater(e1) Igas(e1)Ioil(e1)
WATER
OIL
GAS
cou
nt
rate
hig
h
ener
gy
lev
el,
I(e 2)
count rate low
energy level, I(e1)
Triangle contains all
possible combinations of
oil, water and gas fractions
Triangle contains all
possible combinations of
oil, water and gas fractions
Page 9 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Microwave
Electromagnetic radiation, wavelength from 300 mm to 10 mm (1 GHz to
30 GHz)
The impedance, X, of a capacitor is given by
X = wC + 1/R
Where:
w = Frequency
C = The capacitance
R = Resistance
The capacitive component of this impedance grows in
magnitude with increasing frequency, while the conductive
component is independent of frequency. At high enough
frequency (> 1 GHz), the capacitive component dominate
even in water-continuous emulsions.
• By increasing the frequency even further, the sensitivity to
salinity changes decreases, but at these higher frequencies
and thus lower wavelengths it is only possible to measure over
smaller volumes. Full bore measurements are not possible
anymore and a solution often applied is the use of sampling
lines but this might introduce additional problems with
respect to representative sampling.
Page 10 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Literature Review
Gasch et al (1999)
A good multiphase flow meters should have the following characteristics:
Should be able to work for all flow regimes
Should not be affected by changes in fluid properties (density and
dielectric properties)
Should be non-intrusive system
Robust design
Works in harsh environments
No preconditioning of the flow (“Sever limitation for most applications)
Loh et al (1999)
• “Tomography provides a means of looking inside the flow region
from which local flow information such as volume fraction and
velocity can be extracted”
• “Provides a more accurate means of calculating flow rate and
eliminates the uncertainty in measurement flow rate due to
inability to predict flow profile with existing measurement
methods”
• You need to measure the distribution of the local volume fraction
of the solids and the distribution of local axial velocity
Page 11 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
Loh et al (1999)
Electrical Resistance Tomography Method
Obtains cross sectional images (as used in x-ray radiography)
Enclose the objects to be measured by a number of non-intrusive sensors
Signals produced depend on the position of the component boundaries
within the sensing zone
A mathematical reconstruction algorithm is used to generate the
respective cross sectional images as obtained from the signals observed
by the peripheral sensors
In a conductive fluid, the local conductivity distribution is measured
which then be converted to local volume fraction distribution using
relation such as that developed by Maxwell (1873)
Literature Review
Toral et al (1998) (ESMER Multiphase Flow Meter)
Describes Experimental setup
In calibration:
Training should be done based on a universal database
of multiphase flow features.
Such database may be found on virtual multiphase flow
meters
Conclusions:
ESMER simple in construction. It consists of a straight
pipe with off the shelf sensors.
Accuracy obtained 10-15%
Suited to low cost/medium accuracy application
Page 12 of 12
Section 19 IE250-IH
Liquid & Gas Flowmetering
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 20
OIML Recommendation 117
Page 1 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Section 20
Current Main Suppliers of Multiphase Flowmeters
Types of Multiphase Meters
Full flow multiphase flow meters:
These require no separation of liquid and gaseous phases for their
operation.
Work well only within specified range.
Multiphase flow meters employing separators:
In these meters, gas and liquid phases are first separated and metered
separately using single phase flow meters for gas and liquid (oil+water)
phases
These meters are more expensive and bulky
Page 2 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 3 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 4 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 5 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 6 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 7 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 8 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
Page 9 of 9
Section 20 IE250-IH
Liquid & Gas Flowmetering
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 21
Terminal Custody Transfer
Page 1 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Section 21
Future Developments in Flow Measurement
Liquid and Gas Flow Metering
An important stage in the selection procedure is to list those factors or
constraints which have to be considered. These factors can be divided
into four groups:
Fluid type
Performance requirements
Installation requirements
Environmental and economic constraints
The fluid to be measured has to be specified
Is it a gas, liquid or mixture which is being measured?
What are the properties at normal and exceptional conditions?
Is the fluid hazardous, corrosive or at high pressure?
What is the temperature range and subsequent viscosity density ranges?
What is its electrical conductivity?
Purpose of Measurement and Uncertainty
Does the measurement need accuracy or repeatability?
Is it to satisfy a third party or to improve control of a process?
The flow range required has to be defined. This will include the
maximum and minimum for the measurement.
Page 2 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
The desired uncertainty across different parts of the range has to be
defined.
Installation
The meter's installation requirements are of paramount importance
since virtually all meter types are affected by the surrounding
pipework.
Questions to be asked include:
What straight pipe can be utilised to locate the meter?
Can the existing pipe be split to install the meter?
What is the access to the meter location?
Environmental Considerations
This does not normally mean the effect of the meter on the
environment but this may have to be considered. This is
especially true if the installation is in a hazardous area where
intrinsic safety rating has to be applied.
What effect does the installation environment have on the
meter (e.g. safety of installation and access) together with
the effect of ambient temperature and humidity (maybe no
influence on the meter).
Economic Issues
Page 3 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Value of the fluid may have to be considered. The
measurement may be for process control or
safety/environmental accounting purposes. The measurement
may give process efficiency benefits.
Purchase price of flow meter is of importance.
Other considerations include the cost of secondary
instrumentation, pipe installation costs, including space
requirements, operating costs including maintenance and
spares.
Selection Process
Selection process is rarely straightforward. The five criteria
areas listed above are not exclusive.
Suitable flowmeters for a given application can now be
selected by a process of elimination or by a process of choice.
Often more than one type of flowmeter may appear to be
suitable for a particular application in which case further
deliberation is required.
Page 4 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
An Overview of Different Types of Meter
Differential Pressure Meters
The orifice plate is by far the most widely used type of
flowmeter and can be designed, specified and used within
expectations defined by standards.
It is affected by flow profile and hence needs upstream and
downstream straight installation lengths which can be reduced
by flow conditioners.
The orifice plate will work for liquids and gases and gives
performance in a 1.5 to 2% accuracy class ( at best).
Liquid and Gas Flow Metering
Differential Pressure Meters
Nozzles and Venturis perform in a similar manner but provide
less blockage to the flow.
Regardless of the flow conditions at the flowmeter,
differential pressure devices can use multiple tappings, and
not a pair of single pressure tappings, if high accuracy is
required.
Other Differential Pressure Methods
The variable area meter is cheap for both gas and liquid
applications at the 2% accuracy range.
Page 5 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
For gas the sonic or critical flow nozzle provides a good
calibration reference and also a good measurement device for
mass flow. It has a high pressure drop and is not used for
applications where loss of pressure is important.
Positive Displacement Meters
These provide highly accurate and repeatable measurement of
most clean fluids.
They can be heavy and bulky in larger sizes and hence
expensive. Ideal for batch measurement at high accuracies,
and are generally resistant to pipe installation effects.
Often the only meter to use for high viscosities.
Extensively used for fiscal and custody transfer work.
Turbine Meters
Used for high accuracy applications in both gas and liquid.
Restricted range with viscosities greater than 30 cSt. They are
very repeatable but are viscosity and flow condition sensitive.
Fast response and good repeatability ensures a wide range of
applications from fiscal measurement of hydrocarbon liquids
and gases through to process control.
Can be easily damaged
Page 6 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Oscillatory Meters
In small size pipes, fluidic meters find some specialist niche
applications.
The most common type is the vortex meter, used at the 1 %
accuracy level and provides a good process control meter.
Used in both liquids and gas applications, they are affected by
flow profile and pulsations.
Electromagnetic Meters
Restricted to conductive fluids, these are used extensively in
pipes above 2 inch.
Their wide rangeability and long life without significant drift
makes them the first choice for water distribution systems.
They are relatively unaffected by flow disturbances and a
straight length of about 10 diameters upstream is sufficient to
keep the error caused by a bend or elbow to less than 1 per
cent.
Ultrasonic Meters
Multipath meters provide fiscal standard gas flow
measurement and for lower accuracy applications in oil.
Single-path clamp-on meters often provide the only solution
to non-intrusive measurement but can not be expected to be
better than a 2-5% accuracy class.
Page 7 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
All meters are susceptible to flow profile effects and require
10-30 upstream diameters of straight pipe or suitable flow
conditioners.
Mass Flowmeters
The Coriolis meter provides direct mass measurement of most
liquids. It also measures gas but performs best when the
pressure (density) is high.
Better than 0.4% accuracy this type of meter competes with
positive displacement for liquid applications and some custody
transfer applications.
Meters are not affected by flow profile effects.
Desirable to avoid the vibration of meter, provide firm
clamping and avoid flow pulsations.
Measures mixture density in two phase flows.
Page 8 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Thermal Meters
Two types:
– The low flow gas thermal meters
– Insertion type hot wire types
Generally thermal mass flow meters are not affected by
skewed or swirling flows.
In-line thermal mass flow meters are sensitive to both skew
and swirl and the manufacturers recommendations for
minimum distances up and downstream of sources of
disturbance should be observed.
Faults and Failures
The reading from a flowmeter is often only questioned when
something is obviously wrong, e.g. a zero reading when flow is
present.
Common causes of faults and failures are listed next, firstly
for meter primaries (the meter itself) and secondly for meter
secondaries (the associated instrumentation).
Problems may also be caused by surrounding pipe fittings e.g.
a blocked filter or a faulty isolation valve.
Page 9 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Liquid and Gas Flow Metering
Orifice Plates
Orifice plates are subject to edge rounding by erosion,
buckling by overpressure or thermal stresses, roughening of
the upstream pipe, build-up of dirt, misalignment and partial
blockage of pressure tappings.
Most serious effect is the rounding of the sharp upstream edge
of the plate which causes an increase in discharge coefficient
and hence an underestimation of the flowrate.
Venturi Meters and Nozzles
These devices are subject to roughening and fouling of the
throat with a consequent decrease in the discharge coefficient
leading to an overestimation of the flowrate.
Additionally, like orifice plates, roughening of the upstream
pipe, misalignment and partial blockage of pressure tappings
are problems.
Electromagnetic Meters
These meters are sensitive to fouling of the electrodes (if
wetted). Can use liner.
An order of magnitude change in the conductivity of the
metered fluid can change the calibration factor.
Particular items to check are damage to the insulating liner.
Page 10 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Also required to establish good electrical earthing between
meter body, the fluid, the pipework and the secondary
electronics to provide a common electrical potential.
Turbine Meters
Progressive wear of the bearings changes the meter factor and
linearity.
Partial blocking of the flow passage or material adhering to
the blades will affect the calibration of the meter.
Damage to the blades may occur particularly during cleaning,
and if debris is in the line.
Over-speeding is a primary cause of bearing failure.
Incorrect pulse generation/counting must also be considered.
Vortex-Shedding Meters
Damage to, or adherence of material to the vortex generator
will cause an alteration to the calibration.
Flow pulsations, poor installation and operating below the
minimum Reynolds number are the most common failures.
Positive Displacement Meters
Wear or damage to the rotors or chambers will cause
increased slip and hence an underestimation of the flowrate.
Debris can destroy the meter and block the flow line.
Page 11 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Secondary Devices (Pressure and Temperature)
Pressure lines and tappings are often a source of trouble
particularly at joints and junctions. For differential
measurement very small leaks and blockages can lead to large
measurement errors. The calibration of the pressure
transmitter and the associated readout must be assured.
Errors in temperature may give errors in the calculated
flowrate and hence the correct installation and calibration of
thermometers is vital.
Electrical/Electronic, Electromechanical Devices
Pulse counters are affected by other electrical devices nearby
if the counter leads are not adequately screened.
For the magmeter, zero shift is the most common source of
error. This has been minimised by modern circuitry.
Mechanical counters are usually reliable but slip can occur in
a magnetic coupling between the primary and secondary and
mechanical couplings can break.
Unintentional Generation of Two-phase Flows
A further source of error is the unintentional production of a
second phase, e.g. cavitation in a liquid or condensation in a
gas, air entrainment due to low pressure.
Cavitation occurs after a sudden restriction in the pipeline
such as a partially closed valve.
Page 12 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
If there is a sudden expansion in a pipe carrying a gas which is
near to its saturation pressure, there may be condensation of
the gas. Again this can be prevented by maintaining the static
pressure at an adequate level.
Page 13 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Table 2: Broad Areas of Application
Y = Yes N = No L = Limited
Page 14 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 15 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 16 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 17 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 18 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 19 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 20 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
Page 21 of 21
Section 21 IE250-IH
Liquid & Gas Flowmetering
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 22
Lease Automatic Custody Transfer
Page 1 of 1
Section 22 IE250-IH
Liquid & Gas Flowmetering
Section 22
Future Developments in Flow Measurement
Liquid and Gas Flow Metering
Currently it is estimated that world-wide there is a flowmetering
business worth approximately US $1 billion with expanding sales of the
more sophisticated flowmeters such as electromagnetic, Coriolis and
ultrasonic.
Relatively cheap microprocessors have been embedded into flow
measurement devices to effect operation such as linearisation and
compensation and these devices are commonly referred to as ‘smart’.
Another important feature stems from the fact that the output of the
flowmeter can be assessed and compared with that of the flowmeter
when initially calibrated. This would provide a measure of how far the
performance of the flowmeter was short of its calibrated specification.
In conjunction with the application of, for example, fuzzy logic and the
more recent chromatic methodologies to the interrogation of the output
signals this feature shows great promise for fault diagnosis.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 23
Truck Custody Transfer
Page 1 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
Section 23
Numerical Exercises
Standards Organisations QUESTION 1
LIQUID FLOWING THROUGH A CONVERGING PIPE SECTION
DATA:
V1 = 4 m /s
D1 = 18 inches
D2 = 6 inches
Density of liquid = 850 kg / m3
QUESTIONS:
Determine:
V2 (m /s)
Volumetric flowrate Q (m3 /s)
Mass flowrate m (kg/s)
QUESTION 2
LIQUID FLOWING THROUGH A CONVERGING PIPE SECTION
DATA:
Mass flowrate m = 4 kg /s
D1 = 18 inches
D2 = 6 inches
Density of liquid = 950 kg / m3
QUESTIONS:
Determine:
V2 (m /s)
Volumetric flowrate Q (m3 /s)
Page 2 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
QUESTION 3
METHANE FLOWING THROUGH A PIPE SECTION
DATA:
Line pressure = 4.3 bar
Temperature at some point = 29 C
Gas constant = 518 J /kg K
QUESTIONS:
Determine:
Density of Methane ( kg/ m3 ) at the point
Density of Methane ( kg/ m3 ) at the point if temperature doubled
Density of Methane ( kg/ m3 ) at the point if temperature doubled
and pressure doubled
QUESTION 4
METHANE FLOWING THROUGH A PIPE SECTION
DATA:
D = 20 cm
Length of pipe L = 100 m
Density of Methane = 0.717 kg / m3
Pressure difference across pipe length = 0.1 bar
Friction factor = 0.01
QUESTIONS:
Determine:
V (m /s)
Volumetric flowrate Q (m3 /s)
Mass flowrate m (kg /s)
Page 3 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
QUESTION 5
OIL FLOWING THROUGH A PIPE SECTION
DATA:
D = 20 cm
Length of pipe L = 200 m
Density of Oil = 1090 kg / m3
Mean velocity = 3 m/s
Friction factor = 0.05
QUESTIONS:
Determine:
Pressure difference across pipe length
Volumetric flowrate Q ( m3 /s)
Mass flowrate m ( kg /s)
QUESTION 6
OIL FLOWING THROUGH A PIPE SECTION
WITH INSTALLED ORIFICE PLATE
DATA:
Density of oil = 830 kg / m3
Flowrate = 0.8 m3/s
Discharge coefficient of orifice plate = 0.65
Pipe diameter = 0.6 m
Orifice plate b = 0.5
QUESTIONS:
Determine:
Pressure difference across orifice plate
QUESTION 7
OIL FLOWING THROUGH A PIPE SECTION
Page 4 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
WITH INSTALLED ORIFICE PLATE
DATA:
Density of oil = 830 kg / m3
Pressure difference across orifice plate = 0.5 bar
Discharge coefficient of orifice plate = 0.65
Pipe diameter = 0.6 m
Orifice plate b = 0.5
QUESTIONS:
Determine:
Volumetric flowrate
QUESTION 8
OIL FLOWING THROUGH A PIPE SECTION WITH INSTALLED ORIFICE PLATE
DATA:
Density of oil = 830 kg / m3
Pressure difference across orifice plate = 0.5 bar
Discharge coefficient of orifice plate = 0.65
Pipe diameter = 0.6 m
Orifice plate hole size = 0.31 m
QUESTIONS:
Determine:
Volumetric flowrate
Percentage difference in flowrate compared with Exercise 7
QUESTION 9
PRESSURE CALCULATIONS
Piston in a cylinder
DATA:
Force applied to gas in cylinder = 1000 N
Page 5 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
Internal diameter of cylinder = 10 cms
Ambient pressure = 1 bar
QUESTIONS:
Determine:
1. Absolute gas pressure in Pa
1. Gauge gas pressure in Pa
2. Absolute gas pressure in psi
QUESTION 10
PRESSURE CALCULATIONS- Pressure at base of oil tank
DATA:
Height of oil in tank = 4 m
Density of oil = 1400 kg / m3
Acceleration due to gravity = 9.81 m / s2
Ambient pressure = 1 bar
QUESTIONS:
Determine:
1. For open tank: absolute oil pressure at base in Pa
2. For open tank: gauge oil pressure at base in Pa
3. For closed tank with pressure of 2 bar above oil: absolute oil pressure at
base in Pa
4. For closed tank with pressure of 2 bar above oil: gauge oil pressure at
base in Pa
QUESTION 11
WORK, ENERGY, POWER, CALCULATIONS
Metal block moved along ground
DATA:
Force applied to move block = 100 N
Page 6 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
Distance moved by block = 20 m
Time taken to move block = 12 s
QUESTIONS:
Determine:
Work done in moving block
Energy expended in moving block
Power (in HP) used in moving block
QUESTION 12
TWO-PHASE FLOW EXAMPLE CALCULATION
A vortex flowmeter is metering steam with a quality of 95% at a pressure of
140 psia ( 965 kPa ).
If the mean K factor is 64 pulses / ft3 ( 2295 pulses / m3 ), calculate :
1. The total mass flow if the counter registers 100,000
2. The mass of saturated vapour ( steam )?
SOLUTION
For a two-phase flow, the total flow is calculated from the equation:
Q lb = rtp x pulses / K
The effective two-phase density is given by:
rtp = rg / { X 1.53 + ( 1 - X 1.53 ) rg / rl }
i.e.
rtp = 0.31066 / { 0.95 1.53 + ( 1 - 0.95 1.53 ) 0.31066 / 55.476 }
= 0.33587 lbm / ft3
Page 7 of 7
Section 23 IE250-IH
Liquid & Gas Flowmetering
Hence from standard steam tables at a pressure of 140 psia:
the density of the saturated vapour is rg = 0.31066 lbm / ft3
and the density of the saturated liquid is rl = 55.476 lbm / ft3
1. The total mass flow is then:
Q lb = 0.33587 x 100,000 / 65 = 516.7 lbm
2. The mass of saturated vapour is given by the equation:
( Q lb ) g = X ( Q lb ) T = ( 0.95 ) ( 516.7 ) = 490.9 lbm
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 24
Leak Detection Systems
Page 1 of 3
Section 24 IE250-IH
Liquid & Gas Flowmetering
Section 24
Standards Organisations, Flow Measurement Standards
and References
Standards Organisations
Page 2 of 3
Section 26 IE250-IH
Liquid & Gas Flowmetering
Flow Measurement Standards
API RP550 (INSTALLATIONS OF REFINERY INSTRUMENTS AND CONTROL SYSTEMS)
BS7118 (MEASUREMENT OF FLUID FLOW: ASSESSMENT OF UNCERTAINTY IN CALIBRATION AND USE OF FLOW MEASURING DEVICES)
BS5844 (METHODS OF MEASUREMENT OF FLUID FLOW: ESTIMATION OF UNCERTAINTY OF A FLOWRATE MEASUREMENT)
BS5728 (FLOW OF COLD WATER IN CLOSED CONDUITS) BS1042 (METHODS FOR MEASUREMENT OF FLUID FLOW IN CLOSED
CONDUITS) ISO5167 ORIFICE PLATE/ NOZZLES/VENTURIS) AGA REP NO 3 (ORIFICE PLATE) BS4161 (TURBINE GAS METERS) BS4331 (METHODS FOR ASSESSING PERFORMANCE CHARACTERISTICS OF
ULTRASONIC FLOW DETECTION EQUIPMENT) ISO9330 (MEASUREMENT OF GAS FLOWS BY MEANS OF CRITICAL FLOW
NOZZLES) BS5579 (STANDARD REFERENCE CONDITIONS FOR MEASUREMNT OF
PETROLEUM LIQUIDS AND GASES) BS5792 (FLOW MEASUREMENT USING ELECTROMAGNETIC FLOWMETERS)
Page 3 of 3
Section 26 IE250-IH
Liquid & Gas Flowmetering
References
1. R.W Miller: Flow Measurement Engineering Handbook. Mc Graw-Hill 3rd Edn. ISBN 0-07-042366-0.
2. D.W.Spitzer: Flow Measurement. ISA 2nd Edn. ISBN 1-55617-736-4. 3. Instrument Engineer’s Yearbook. Inst MC. ISBN 0-904457-33-8
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 25
API Standards
Page 1 of 2
Section 25 IE250-IH
Liquid & Gas Flowmetering
Section 25
Cavitation and Flashing
Cavitation occurs in two distinct stages. In the first stage voids or cavities are formed, and in the second stage these collapse or implode back into an all-liquid state. Two types of cavitation may occur, gaseous or vaporous, both types requiring a nucleating agent for inception. These nucleating points enlarge into finite cavities within the liquid.
Most liquids contain solid contaminants so that the necessary nuclei for incipient cavitation are nearly always present. The inception of cavitation may be delayed significantly if the liquid has been carefully degassed, polymers added, or the liquid maintained under high pressure for a period of time for the gas to completely dissolved.
If the cavitation process ceases before the second stage, so that vapour persists downstream of the region where bubble collapse normally takes place, the process is called flashing. Since flashing is directly related to the first stage of cavitation, the theory of cavitation also applies to flashing.
When decreased line pressure approaches the vapour pressure of a liquid in a pipe, cavitation begins. This is essentially local boiling caused by decreasing pressure rather than by increasing temperature. The resulting formation and collapse of the vapour cavities is responsible for the audible noise in the pipeline. Excessive cavitation destroys piping, restricts flows, and ruins turbine blades.
Cavitation occurs whenever pressure has been reduced by, for example, flow separation, valves, vortex elements and differential pressure flowmeters. Imploding pressures can reach 100,000 psi.
Dissolved gases and gas bubbles assist in the onset of cavitation. With gas concentrations of only 30 parts per million, fluids will cavitate at higher static pressures than for the liquid alone.
Page 2 of 2
Section 25 IE250-IH
Liquid & Gas Flowmetering
Cavitation number is defined as: s = 2 ( p – pv ) / r V2 p is the local static pressure pv is the local vapour pressure r is the fluid mean density V is the fluid mean velocity Usually cavitation begins with very small bubbles isolated in a small section of the flowmeter. As the cavitation number decreases, formation becomes more rapid with bubble size increasing. For cavitation numbers below a certain value (called the incipient cavitation number sI) cavitation becomes increasingly destructive to both piping and flowmeters. The addition of small amounts of polymers has been seen to reduce both sI and the noise.
In a flashing liquid, the volume of vapour is frequently greater than the volume of liquid, so that the liquid droplets tend to achieve the high velocity of the vapour. These high velocity droplets impact on the pipe or flowmeter surface causing deformation of the surface. Damage due to flashing is usually in the section downstream of the flowmeter and piping here is often pitted. For liquids near saturation, flashing sometimes begins upstream and the entire flowmeter body can be affected. So proper choice of flowmeter material is essential.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 26
Standards Organizations, Flow Measurement
Standards and References
Page 1 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Section 26
Pipeline Requirements and Installation Notes for Dry-Type
Differential Transmitters
General Requirements
For liquid flows in a horizontal pipe ( Figs. 1 and 2 ), the pressure taps should be located at the sides of the pipe, with no more than a ±45° orientation. For horizontal clean gas flows ( Fig. 3 ), the pressure taps should be vertical; for vapors (steam, ammonia) and dirty or condensable gases ( Fig. 4 ), the taps should be located at the side. For vertical pipe installations, the pressure taps can be at any radial position around the pipe circumference ( Figs. 5 to 8 ). The differential-pressure transmitter should be located as close to the taps as possible. This improves the speed of response and reduces the possibility of resonance or attenuation within the leads. Prefabricated manifolds are available for easy close-coupled installation (Fig. 9). Lead lines should be of the same bore, no less than 0.25 in (6 mm) in diameter for clean liquids. For condensable vapor flows, where gas bubbles may be liberated, the diameter should be no less than 0.4 in (10 mm). For long, liquid-filled lines, a gradient of 1 in/ft (80 mm/m) is recommended to allow gas bubbles to rise back into the flow line. If the fluid is of medium to high viscosity (5 to 100 cP), the slope should be increased to 2 to 4 in/ft (160 to 320 mm/m). The tubing bore should be increased to the ISO-recommended values if long lead lines are necessary.
Page 2 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Page 3 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
General Requirements
The two lead lines should be close together and lagged, if necessary, to reduce density variations due to temperature differences. Any head difference between leads alters the differential, although zeroing under flowing pressure and temperature usually reduces this error.
For clean liquids and dry gases, lead lines are purged through transmitter vents.
If the flowing gas or liquid must be isolated from the measuring element because of corrosion, dirt, sediment, or condensation, seal fluids are used. Several slack, flush-mounted diaphragm seals are also available for isolation.
A seal fluid serves two purposes:- to isolate the process and to provide protection against freezing. The most common seal liquid for oils is a mixture of 50 percent water and 50 percent ethylene glycol or glycerine, or, for lower-temperature protection, a mixture with 60 percent ethylene glycol.
The ethylene glycol mixture has a specific gravity of about 1.07; the glycerine, about 1.13. The 50 percent ethylene glycol mixture freezes at -35°F (-37°C), and the 60 percent mixture at -56°F (-50°C). The 50 percent glycerine mixture freezes at -9.4°F (-23°C) and the 60 percent at -56°F (-49°C).
For water and low-gravity aqueous solutions of salts and acids, dibutyl phthalate has been found highly satisfactory. Dibutyl phthalate has a specific gravity of 1.05, freezes at -31°F (-35°C), and has a boiling point of 612°F (322°C).
For liquids with a specific gravity greater than 1.01 heavier seal fluids must be found. Chloronaphthalene or Halowax oil, various Arochlors, transformer sealing fluids, Kel-F oil (trifluorochloroethylene polymers), fluorolubes, and acetylene tetrabromide have been used, but many are toxic, highly viscous, or have other disadvantages.
No really satisfactory sealing medium for large displacement secondary elements (wet-type meters) has been found for materials such as concentrated sulfuric acid, although lighter oils, such as Nujol or other acid and caustic treated oils, have been used.
Use of oil lighter than the flowing fluid introduces serious maintenance problems.
Page 4 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Page 5 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Table 8.3 Recommended Minimum Internal Diameters of Lead Line
Page 6 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Page 7 of 7
Section 26 IE250-IH
Liquid & Gas Flowmetering
Pressure Taps For gas and vapor flows a pressure-tap connection is required if a pressure compensation is to be made. The precautions outlined for the differential-pressure connection should be followed. The pressure transmitter is usually connected via a tee to either the upstream or downstream pressure lead line. The tap selected depends on whether an upstream or downstream gas expansion factor is to be calculated. A second pressure tap is recommended when using meters that have a sizable change in volume as the differential increases (bellows, manometer type, etc.). The presence of pulsations, or severe line noise, may result in cross talk between the differential-pressure and pressure meters that can result in errors in both measurements.
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 27
Contoured Devices
Page 1 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
Section 27
Contoured Devices
These have the advantage of sweeping solids through the throat and of
reducing permanent pressure loss. They are normally more rugged than orifice
meters and usually better therefore for metering steam or other high velocity
applications.
Flow Nozzles
Several flow-nozzle contours are available. The ASME wall-tap flow nozzle
(either low- or high-b series) is preferred in the United States, while in Europe
the ISA 1932 design is widely used.
In the United States, the ASME low-b-series nozzle is sometimes modified to
have throat taps, and this has become the accepted standard for testing steam-
turbine performance.
Page 2 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
Page 3 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
ASME Long-Radius Wall-Tap Nozzle. The ASME flow nozzle has a contoured
elliptical inlet in which the curvature is the quadrant of an ellipse. For beta
ratios from 0.2 to 0.5 (the low b series), the design is as shown in Fig. 9. For
beta ratios between 0.45 and 0.8 (the high b series), the design is as shown in
Fig. 10.
The nozzle wall and flange thickness should be sufficient to prevent distortion
caused by pipeline pressure, temperature, or bolting strains. The nozzle should
be well centered in the pipe, and the installation requirements relative to
upstream piping conditions, thermal wells, etc., should be followed for good
measurements.
It is important that the downstream pressure tap be inside the exit. Also,
outward widening of the cylindrical throat should be avoided, since this causes
a rising discharge coefficient at high Reynolds numbers.
The throat taper, if any, should always decrease the throat diameter toward
the exit, with no bell mouth or diameter increase.
Discharge-coefficient data has been reduced to an empirical equation for pipe
Reynolds numbers greater than 10,000. Teyssandier (1986) has presented data
that indicates that these equations are valid for line sizes of 1.5 to 3.4 in (38 to
87 mm) within the stated tolerance. This equation is graphed in Fig. 11. For
low Reynolds numbers, Benedict's (1966) equation, which was empirically fitted
to the ASME low-Reynolds-number data, may be used.
This equation is:
C = 0.19436 + 0.152884 ln Rd - 0.0097785 (ln Rd)2 + 0.00020903 (ln Rd)3
Figure 13 is a plot of this equation.
Page 4 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
Classical Venturi Tube
Classical venturis are shown in Fig. 15. They are grouped as:
1. Classical venturi with rough-cast inlet, recommended for line sizes of 4
to 32 in (100 to 800 mm)
2. Classical venturi with machined inlet, recommended for line sizes of 2 to
10 in (50 to 250 mm)
3. Classical venturi with rough-welded sheet-iron inlet, for line sizes of 8 to
48 in (200 to 1200 mm)
Page 5 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
Venturis in the first two groups are cast in a sand mold, and the inlet
may be left as cast (group 1) or machined (group 2).
• Although standards limit the maximum line size to 48 in (1200
mm), classical Venturis have been fabricated for use in 120 in
(3000 mm) lines.
• In the United States, the rough-cast inlet is almost always used
while in Europe all three groups are commonly used.
• The exit cone (recovery cone) may have an included angle
between 7° and 15° with 7° being preferred for minimum
permanent pressure loss.
• The 7° cone may be shortened to reduce lay-in length without
significantly altering recovery.
Page 6 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
Page 7 of 7
Section 27 IE250-IH
Liquid & Gas Flowmetering
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course
Section 28
a. Computer System Control A b. Computer System Control B
Page 1 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Section 28a
Computer System Control A
Control Systems
• Control System is a device or set of devices which are used to command or regulate the behavior of other devices or systems.
• Earlier Control Systems are Manually controlled, now they are independent of human involvement.
Ex: 1. Flowmeter control system 2. A motor driving the load 3. Washing machine
Typical Control System
Signal
Conditioning
Analog
Control
Hardware
Actuator Plant
Analog Sensors
TransducersSignal
Conditioning
outputR Error
PV
Page 2 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Elements of Control System
Signal Conditioning: Amplification, filtering, attenuation and multiplexing.
Controller: A device that carries out the computation of the control signal.
Actuator: Object such as motor that provides the power to control a process.
Sensor: Device such as thermostat that computes a signal proportional to a physical variable such as temperature.
Transducer: an electronic device that converts energy from one form to another.
Generic Block Diagram of Digital Control System
Pre-
FilterA / D Computer D / A
Smooth
Filter Plant
Sensor
Anti-
Alias
Filter
A / D
Clock
outputR
Page 3 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Elements of Digital Control System
Pre-filter: Filter that precedes the control loop. A/D: It converts continuous signal to digital signal. Digital Computer: It carries out computation, and consists of a processor,
a memory, and I/O devices. D/A: It converts digital signal to continuous signal. Smooth Filter: used to remove noise or other high frequency components
of a signal. Sensor: Device that outputs a signal proportional to a physical variable. Anti Alias Filter: Filter designed to remove signals that might cause
aliases before they are sampled.
Simplified Digital Control System
Digital
ComputerDAC
Smooth
FilterPlant
Digital
Sensors
Digital
Multiplexer
Clock
R OUTPUTFCE
Modes of Closed Loop Control
Closed loop control can be:
Manual
On-Off
PID
Advanced PID (ratio, feedforward, etc….)
The algorithm determines the controller output.
Page 4 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Basic Elements of Process Control
Controlling a process requires knowledge of four basic elements, the process itself, the sensor that measures the process value, the final control element that changes the manipulated variable, and the controller.
Page 5 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Control Elements These are the devices the controller operates:
Pneumatic valves, solenoid valves, rotary valves, motors, switches, relays, variable frequency drives.
Controllers These are the devices that do the controlling:
• Programmable Logic Controllers (PLCs) • Programmable Automation Controllers (PAC) • Distributed Control Systems (DCS) • Proportional, Integral, Derivative (PID) Controllers • Supervisory Control and Data Acquisition (SCADA) • Energy Management Systems (EMS)
Operation of Closed Loop Digital Control System
• Basic operation is described by an a Flowmeter Control System.
• Please provide block diagram and brief description of the operation (see
preliminary example below.
Page 6 of 6
Section 28a IE250-IH
Liquid & Gas Flowmetering
Page 1 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Section 28b
Computer System Control B
Basic Control Concepts
TOPICS
Introduction Variables Basic Elements Manual Control Feedback Control System Responses ON – OFF Control Three Term Control
Introduction
This chapter introduces the basic concepts encountered in Process Control.
Some of the standard terminology is also presented
Page 2 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Control History
Early development of feedback control by James Watt in Scotland using a governor on a steam engine in about 1775. (Flywheel principle)
Broader use of automatic control began to be made in the late 1920’s and the first general, theoretical, treatment of automatic control was published in 1932.
New technologies have created a transformation in control engineering with the advent of DCS and PLC systems.
The theory of automatic control has also developed in parallel with these new technologies.
Page 3 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Variables
The operations which are associated with process control have always existed in nature, examples are blood pressure, temperature & heart rate etc.
Early forms of process control included some person monitoring a fire to keep up a temperature. This could be considered a version of Manual Control.
The development of automatic control only become a reality when people learned to adapt automatic regulatory procedures to manufacture products or process materials more efficiently.
Automatic control assumes no human intervention.
Variables Involved There are three main terms to consider 1. Controlled Quantities/Variables 2. Manipulated Quantities/Variables 3. Disturbances
Controlled Quantities
Also referred to as Controlled Variables. These are the streams or conditions which the operator wishes to control
or maintain at some level. Controlled variables include such parameters as temperature, pH,
moisture, level, position, flow weight and speed etc. For each controlled there must be a desired value known as a SET-POINT
or reference value.
Page 4 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Manipulated Quantities
For each controlled variable there is a manipulated variable such as a flow rate.
This manipulated variable is usually controlled through the use of a control valve.
Disturbances
Disturbances enter the process and cause change away from the set-point.
Typical disturbances include change in temperature or pressure or feed-stock.
The automatic control system must therefore alter the manipulated variable so that the set point is maintained in spite of these disturbances.
Also, the set point may be moved, in which case the manipulated variable will need to be changed to adjust the process to the new value.
Manipulated Variable
For each controlled variable the control system operator selects a
manipulated variable which can be paired with a controlled variable. Often the choice is obvious, such as manipulating the flow of fuel to a
home furnace to control the temperature of a house. Sometimes the choice is not so obvious and can only be determined by
someone who understands the process under control. The pairing of manipulated and controlled variables is performed as part
of the process.
Basic Elements
Elements of a Process Control System
A control loop is a self-contained system. Purpose is to maintain a process at a given value. Usually consists of a transmitter for measurement. A controller to evaluate. A control valve which can be changed by the controller.
Page 5 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Basic Control Concepts
Basic Elements There are four essential elements in any process control system. 1. Process 2. Measurement 3. Evaluation 4. Control
Process
In general, a process is an assembly of equipment and material and is related to some manufacturing operation or sequence.
In the case of a tank with a liquid, the level of this liquid is influenced by the flow into and out of the tank.
Any given process can involve dynamic variables and it may be desirable to control all of them.
In most cases, controlling one variable would be sufficient to control the process within acceptable limits.
Page 6 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Measurement TO CONTROL ANY PROCESS IT FIRST HAS TO BE MEASURED
Measurement means the conversion of a process variable into an analogue or digital signal by means of a sensor or transmitter or both.
The result of any measurement is the conversion of a dynamic variable into some proportional information which is required by some other elements in the process control loop or sequence.
Evaluation
In the evaluation step of a process control sequence, the measurement is examined and compared with the desired value or set-point.
The amount of corrective action required to maintain proper control is determined.
A controller is used for this evaluation. This controller can be pneumatic, mechanical or electronic and would be mounted in a panel.
It can also be part of a computer control system, in which case the control function is performed by software.
Control Element
The control element in a control loop has the most direct effect on the process.
Receives a signal from the controller and transforms this to a proportional operation which is performed on the process.
In most cases, the final element is a control valve which adjusts a flow in a pipeline, for example.
Other final elements include: electrical motors, pumps and dampers. In a typical home heating system, the controlled variable is the room
temperature. A number of disturbances cause the room temperature to vary, e.g.,
outside ambient temp., the number of people in the room or the activity taking place inside the room.
The automatic control system is designed to manipulate the fuel flow to the furnace in order to maintain room temperature at the desired set-point.
Note: Temperature is being controlled and flow rate is being varied.
Page 7 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Basic Control Concepts
Manual Control
Typical Manual Control IT IS CONSIDERED USEFUL TO REVIEW THE MANUAL CONTROL OF A PROCESS AT THIS STAGE.
There must be an indication of the process which can be used as a measurement.
The operator uses this indication to decide what change is required. The set-point is in the mind of the operator.
Page 8 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Manual Control
The operator compares these two values and changes the final element
accordingly. There are many problems associated with this form of control.
Basic Elements
Page 9 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Feedback Control
THE SIMPLEST WAY TO AUTOMATE THE CONTROL OF A PROCESS IS THROUGH FEEDBACK CONTROL.
Sensors are used to measure the actual value of the controlled variable. This value is transmitted to the feedback controller. The controller makes a comparison between this measurement and the
desired value which has already been established. Based on the difference (error) between these two values, the controller
sends a proportional output to the control value.
Page 10 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Feedback Control
ADVANTAGES OF FEEDBACK CONTROL
It is not essential to know what disturbances will affect the process. Also, the relationship between the final control element and the process
is not an issue. Standard hardware can be used for almost any application. The principles of feedback control apply to all types of process control
instrumentation. Traditional, stand-alone feedback controllers offer the simplest
approach to automatic control.
Page 11 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Feedback Control
System Responses
General Requirements of a Control System
The primary requirement of a control system is that it must be reasonably stable.
The speed of response must therefore be fast. The response must also show reasonable damping. A control system must also be capable of reducing a system error to zero
or to a value close to zero. System Error The system error (e) is the difference between the value of the
controlled variable set-point (SP) and the value of the process variable (PV).
The system error is expressed as: e(t) = PV(t) – SP(t) where (t) is a function of time.
Page 12 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
System Error
System Response
The main purpose of a control loop is to maintain some dynamic process variable at a prescribed operating point or set-point.
System response is the ability of a control loop to recover from a disturbance which causes a change in the controlled variable.
There two categories of good response: 1. Under-damped (cyclic response) 2. Damped
Page 13 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
System Responses
Page 14 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Control Loop Design Criteria
Many criteria are employed to evaluate the response of a process control loop to an input change.
The most common of these include: Settling time Maximum error Offset error Error area The settling time is defined as the time the process control loop needs to bring the PV back to within an allowable error.
The maximum error is simply the maximum allowable deviation of the dynamic variable.
Most control loops have inherent linear and non-linear characteristics which prevent the system from returning the PV to the SP after a system change. This is called offset error.
The area error is the area between the response curve and the set-point line.
System Responses
Page 15 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
ON – OFF Control
Discrete controllers are the most basic form of control and have only two modes or positions, ON and OFF.
A common example is a typical electric iron. When the temperature of the iron falls below the manual setting, the
iron switches ON. When the temperature reaches the desired value (or SET POINT), the
iron switches OFF. This type of control does not actually hold the temperature at the
required value, but keeps the variable within proximity of the SET POINT in what is known as a DEAD ZONE.
System Responses
Page 16 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
ON – OFF Control
The expression for ON - OFF control can be stated as
e = SP - PV where: e = Error SP = Set Point PV = Process Variable In the ON – OFF control mode, the valve is open when the error (e) is positive and the valve is closed when e is negative.
Page 17 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control
Proportional Only Control
A better system is required to overcome the sudden changes of ON – OFF
control. The lack of precise control suggests that an alternative approach is
required. Proportional Control initiates a corrective action which is proportional to
the change in error or deviation of the process from the set-point.
Page 18 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Proportional Only Control
Page 19 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control
Proportional Control
Proportional Gain
In electronic controllers, the proportional action is typically expressed as proportional GAIN.
Proportional Gain answers the question “What is the percentage change of the controller output, relative to the percentage change in controller input?”
Proportional Gain is expressed as Gain (Kc) = ∆ Output % / ∆ Input %
Proportional Band
Proportional Band (PB) is another way of representing the same information and answers the question “What percentage of change of the controller input span will cause a 100% change in controller output?”
PB is expressed as ∆ Input (% span) for 100% ∆ Output
Page 20 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control Proportional Control
Proportional action is limited in the sense that the control action only responds to a change in the magnitude of the error.
Proportional action will not return the PV to the SP. It will however, return the PV to a value which is within a defined span (PB) around the PV.
Page 21 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control Proportional Control
Proportional Plus Integral Control
It would be an improvement if the controller adjusts the controller to eliminate off-set.
It would also be an advantage to have the controller respond at a speed proportional to the size of the error.
This added control function is called reset or integral (reset is the older term).
This function also eliminates the offset. Shortened to P + I If we assume a step change in set- point at some point in time. Initially there is a sudden change in in valve due to proportional action
(equal to Kc x e). At the same time, the integral portion of the controller, sensing an error,
begins to move the valve at a rate, proportional to the error, over time. If the error is constant, the correction rate will also be constant.
Page 22 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Proportional Plus Integral Control
When time is used to express integral or reset action, it is called ”reset time”.
Quite commonly, the reciprocal is used in which case it is called “reset rate” in “repeats per minute”.
This term refers to the number of times per minute that the reset action is repeating the valve change produced by proportional action alone.
Process control systems personnel refer to reset time as integral time and denote it by the symbol “Ti”.
The P + I controller includes the characteristic of the I controller. This allows the advantages of both controller types to be combined, fast
reaction and compensation of the remaining system deviation. For this reason, the P + I controller can be used for a large number of
control applications. I addition to proportional gain, the P + I controller has a further
recognisable value which indicates the behaviour of the I component – the reset time (integral action time)
Page 23 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Proportional Plus Derivative Control
A further function can be added in the form of rate or derivative control. This control function produces a corrective action which is proportional
to the rate of change of error. It should be noted that this correction only exists while the error is
changing, it disappears when the error stops changing, even though there may still be a large error.
Commonly referred to as P + D control. Some large and / or slow processes do not respond well to small changes
in controller output. For example, a large thermal process, such as a heat exchanger, may
react very slowly to a small change in controller output. To improve response, a large initial change in controller output may be
applied. This is the function of the derivative mode. If we assume, the set point is changing at a constant rate. Derivative action contributes an immediate valve change which is
proportional to the rate of change of the error. This would be equal to the slope of the set-point line (the error). As the error increases, the proportional function contributes additional
control valve movement. At a later stage, the contribution of proportional action will have
equaled the initial contribution of the rate action. This is called derivative time td.
Page 24 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Proportional plus Derivative Control Summary
Derivative (Rate) action is a function of the speed of change of the error. The units are expressed in minutes. The action is to apply an immediate response which is equal to the
proportional plus reset action that would have occurred some number of minutes in the future.
The advantage of a rapid output is that it reduces the time which is required to return the PV to the SP in a slow process.
Proportional Plus Integral Plus Derivative Control
Deciding which control action is required for a particular application depends on the characteristics of the process being controlled.
PID control should NOT be used for “noisy” processes or on one which has stepwise changes because the derivative action is based on the measurement of rate of change. This could lead to unstable control.
PID control is used on processes which respond slowly. Temperature control is a common example of PID control. The derivative
action shortens the time taken for the process to respond. In addition to the properties of the P + I controller, the PID controller is
complemented by the D component. This takes the rate of change of the system into account. If the system deviation is large, the D component ensures a momentary
high change in the manipulated variable. While the influence of the D component falls off immediately, the
influence of the I component increases slowly. If the change in system deviation is slight, the response of the D
component is negligible. This behaviour has the advantage of faster and more accurate
compensation of system deviation in the event of changes or disturbance variables.
The disadvantage is that the control loop is much more prone to oscillation and that optimum tuning is therefore more difficult.
Page 25 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control
Page 26 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Three Term Control
Summary
Page 27 of 27
Section 28b IE250-IH
Liquid & Gas Flowmetering
Summary
COURSE RECAP Day 1
0730 - 0800 Registration & Coffee
0800 - 0815 Welcome & Introduction
0815 – 0830 PRE-TEST
0830 - 0930 Flowmetering Overview Introduction to Pipeline Flowmetering with Highlighted Problem Areas
0930 - 0945 Break
0945 - 1045 Introduction to Process Measurement Accuracy, Hysteresis, Linearity, Repeatability, Response, Traceability, Confidence, Resolution, Calibration, Process Symbols
1045 – 1230 Measurement of Pressure Static, Dynamic, Total Pressures, Commercial Pressure Gauges
1230 - 1245 Break
1245 - 1330 Measurement of Temperature and Density Commercial Gauges
1330 - 1420 Flow Measurement Laminar Flows & Turbulent Flows, Velocity Distributions, Reynolds Number Worked Examples, Volume, Mass, Total Flows, Viscosity, Cavitation
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day One
Day 2
0730 - 0915
Fluid Mechanics of Pipe Flows
Fitting Losses ● Newtonian & Non-Newtonian Flows ● Flowmeter
Classification ● Worked Examples
0915 - 0930 Break
0930 - 1045
Flowmeter - Differential Pressure Type
Elementary Theory Based on Bernoulli’s Equation & Continuity ● Orifice
Meters ● Critical Flow Element ● Laminar Flow Element
1045 – 1230
Flowmeter - Differential Pressure Type (cont’d)
Venturi Meters ● Flow Nozzles ● Low Loss Devices ● Variable Orifice
Meters ● Variable Area Meters ● Pitot Tubes & Pitot Static Tubes ●
Target Flowmeters ● Drain Holes and Vents
1230 - 1245 Break
1245 - 1420 Flowmeter – Variable Area Operating Constraints & Performances, Advantages and Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Two
Day 3
0730 - 0830
Flowmeter - Fluid Oscillatory Flowmeters
Fluidic Meters ● Vortex Shedding Meters ● Operating Constraints &
Performances ● Advantages & Disadvantages
0830 - 0930 Flowmeter - Rotary Inferential Meters
Turbine Flowmeters ● Miscellaneous Designs ● Advantages & Disadvantages
0930 - 0945 Break
0945 - 1130
Flowmeter - Electromagnetic Flowmeters
Principle of Operation ● AC & Pulsed DC Types ● Applications &
Operating Constraints and Performances ● Advantages & Disadvantages
1130 - 1230 Flowmeter – Positive Displacement Flowmeters Helical Gear Meter, Nutating Disc Meter, Piston Meter, Rotary Meter, Advantages & Disadvantages, Applications, Worked Examples
1230 - 1245 Break
1245 - 1330 Flowmeter - Ultrasonic Flowmeters
Doppler Type ● Time-of -Flight Type ● Clamp-on Type ● Applications ● Advantages & Disadvantages
1330 - 1420
Flowmeter - Mass Flow Measurement
Coriolis Flowmeters ● Hot Wire Anemometer & Thermal Profile Meter ●
Applications ● Advantages & Disadvantages
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Three
Day 4
0730 - 0830 Flowmeter – Miscellaneous Devices Cross Correlation Methods, Tracer Methods, Weighing Methods Velocity Profile Integration Techniques, Laser Doppler Systems
0830 – 0930
Flowmeter Calibration
Gravimetric Methods for Liquid Flowmeters ● Volumetric Methods for Liquid
Flowmeters ● Use of Pipe Provers ● Methods for Gas Flowmeters ●
Critical Flow Nozzle ● Velocity Traversing Technique ● Clamp-on Ultrasonic Flowmeter
0930 - 0945 Break
0945 - 1030
Flowmeter Installation Guidance
Introduction ● Pipe-Flow Disturbances & Other Sources of Error Effects of
Installation on Specific Flowmeters ● Remedial Actions & Use of Flow Conditioners
1030 – 1130 Flowmeter Costs and Flowmeter Selection
Initial Considerations ● Flowmeter Selection Procedure ● Additional Factors
1130 - 1230
Quality Assurance and Standards
Traceability & Hard Standards ● Flow Standards ● UK National
Measurement Systems ● Accreditation Process
1230 - 1245 Break
1245 - 1420 Introduction to Multiphase Flow Measurement Description of Multiphase Flows, Definitions of Various Associated Terms, Flow Pattern Classification, Flow Regimes, Multiphase Measurement
Problems, Multiphase Meter Classification
1420 – 1430
Recap Using this Course Overview, the Instructor(s) will Brief Participants about the Topics that were Discussed Today and Advise Them of the Topics to be Discussed Tomorrow
1430 Lunch & End of Day Four
Day 5
0730 - 0830 Basic Concepts of Multiphase Flows & Multiphase Flowmeters Response of Single-Phase Flowmeters in Multiphase Flows, Wet Gas Flow Measurement, Application of Two Flowmeters for Multiphase Flows
0830 - 0930 Current Main Supplier of Multiphase Flowmeters Overview of Different Devices & their Limitations/Advantages
0930 - 0945 Break
0945 - 1230
Selection of Flowmeters
Classification of Flowmeter Types ● Selection Considerations ● Installation
Planning & Installation ● Faults & Failures ● Application Tables
1230 - 1245 Break
1245 - 1345
Future Developments in Flow Measurement
Flowmeter Developments ● Secondary Instrumentation ● Signal
Acquisition & Processing from Single-Phase Flowmeters ● Utilization of Unconditioned Signals from Single Phase Flowmeters in Multiphase Flows
1345 – 1400 Course Conclusion Using this Course Overview, the Instructor(s) will Brief Participants about the Course Topics that were Covered During the Course
1400 - 1415 POST-TEST
1415 – 1430 Presentation of Course Certificates
1430 Lunch & End of Course