G Fl M tG Fl M tGas Flow MeasurementGas Flow Measurement

K l St tKarl StappertAmericas Flow Solutions AdvisorEmerson Process Management

Gas Flow MeterGas Flow MeterT h l i A dT h l i A dTechnologies AgendaTechnologies Agenda

Coriolis TurbineUSM

Orifice PD / Rotary

Orifice Meters Orifice Meters -- AGA3AGA3Orifice Meters Orifice Meters -- AGA3AGA3

Orifice Gas Metering STD AGA3

Part 1 - Equations and Uncertainty Pub: Sept 2012

Part 2 – Specification and Installation Pub: April 2000

Part 3 – Natural Gas Applications Pub: Sept 1992 (Under Revision)

Part 4 – Background & DevelopmentPart 4 Background & Development Pub: Sept 1992 (Under Revision)

Adopted by American Petroleum InstitutePetroleum Institute Part of the Manual on Petroleum

Measurement Standards (MPMS) API MPMS Chapter 14.3

Prescriptive Standard

OrificeOrifice –– Theory of OperationTheory of OperationOrificeOrifice –– Theory of OperationTheory of Operation

Orifice Orifice –– Meter TubeMeter TubeOrifice Orifice –– Meter TubeMeter Tube

Orifice Orifice –– Meter Tube w/Tube BundleMeter Tube w/Tube BundleOrifice Orifice –– Meter Tube w/Tube BundleMeter Tube w/Tube Bundle

Orifice Orifice –– Meter Tube w/Flow ConditionerMeter Tube w/Flow ConditionerOrifice Orifice –– Meter Tube w/Flow ConditionerMeter Tube w/Flow Conditioner

Orifice Orifice –– Meter TubeMeter TubeDiameter & RoughnessDiameter & RoughnessOrifice Orifice –– Meter TubeMeter TubeDiameter & RoughnessDiameter & Roughness

Dm

Dm < 12” Max Roughness < 300 micro inches, If Beta < 0.6 Max Roughness < 250 micro inches, If Beta > 0.6 Min Roughness > 34 micro inches

Dm > 12” Max Roughness < 600 micro inches If Beta < 0 6Max Roughness < 600 micro inches, If Beta < 0.6 Max Roughness < 500 micro inches, If Beta > 0.6 Min Roughness > 34 micro inches

Orifice Orifice –– Plate SpecificationsPlate SpecificationsOrifice Orifice –– Plate SpecificationsPlate Specifications

Roughness < 50 micro inches

Flatness <(0.005(Dm-dm))

Bevel (45 Deg + 15 Deg)

Bore Thickness, Roundness, EccentricityBore Thickness, Roundness, Eccentricity

Ddm

750100Dm

..

Orifice Orifice –– Reynolds NumberReynolds NumberOrifice Orifice –– Reynolds NumberReynolds Number

Ideal Profile – Turbulent

VD

Re

Where: Re = Reynolds NumberDensity Flowing = Density Flowing

V = VelocityD = Pipe Diameter = Viscosity

newDD

Re

Orifice Orifice –– AGA3 Practical Uncertainty AGA3 Practical Uncertainty Orifice Orifice –– AGA3 Practical Uncertainty AGA3 Practical Uncertainty 2” Lower Beta

2309391450

Dd .

".".

Minimum Beta Ratio 2” Pipe

Orifice Orifice ––AGA3 Coefficient of Discharge UncertaintyAGA3 Coefficient of Discharge UncertaintyOrifice Orifice ––AGA3 Coefficient of Discharge UncertaintyAGA3 Coefficient of Discharge Uncertaintyg yg yg yg y

Coefficient of Discharge Uncertainty (Cd) Relative Change in Cd Uncertaintyw/Reynolds Number

VD

Re

Where: Re = Reynolds NumberWhere: Re = Reynolds Number = Density FlowingV = VelocityD = Pipe Diameter = Viscosity

Orifice Orifice ––AGA3 Expansion Factor ( ) UncertaintyAGA3 Expansion Factor ( ) UncertaintyOrifice Orifice ––AGA3 Expansion Factor ( ) UncertaintyAGA3 Expansion Factor ( ) UncertaintyYp ( ) yp ( ) yp ( ) yp ( ) y

Old Equation

f3PNP04.New Equation

Y

f3PN

Orifice Orifice –– Advantages & DisadvantagesAdvantages & DisadvantagesOrifice Orifice –– Advantages & DisadvantagesAdvantages & DisadvantagesAdvantages DisadvantagesRange Adjustable (plate change) Plate sealing ring incompatabilityWell Documented in standards + .75% Pulsating Flow – Over registrationWell Documented in standards .75% Pulsating Flow Over registrationIndustry acceptance Can not handle dirty processesLow unit capital cost Low rangeability (single plate)No moving parts High Pressure LossDry calibration acceptable Flow profile & dirty process sensitiityy ca b a o accep ab e o p o e & d y p ocess se s yNo limits on pressure, temp, and size Requires long meter tube/Flow ConditionerMechanically robust Over-range – partial loss of measurment½ Volumetric / ½ Mass Meter Potential service interruptionLow Power High Installation & OpEx

• Approximately 3-1 Turndown single Beta

• Approximately 28:1 turndown with plate changes over a Beta range of 0.2 to 0.6 (Custody Transfer Beta Range) 3max

DP

DP

g pField meter verification Can be damaged with high flow rates.

0.6 (Custody Transfer Beta Range)

• Approximately a 0.7% meter degrading rapidly when

• Orifice diameters are > 0.45 (Approximately 0.225 beta on 2” Orifice)

• Pressure decreases below 100 psia and DP increases above 50” H2O

liveDP

H2O

• Turndown = 3 when DP Max = 150” H20 and DP Min = 16” H20

• 150” H2O = 5.4 PSI

Turbine Meters Turbine Meters -- AGA7AGA7Turbine Meters Turbine Meters -- AGA7AGA7

Turbine Gas Metering Recommended Practice

Revised December 2006

Significant ChangeSignificant Change

Calibration Should be performed at flowing density or flowing Reynolds numbers

Performance Based Performance Based Specification

Turbine Turbine –– Theory of OperationTheory of OperationTurbine Turbine –– Theory of OperationTheory of Operation

/

ACFPulses

PulsesTurbACF / ACFPulses

Flow

ACFSCFffb

bbf

ZTPZTP x

xx x x

ffb ZTP x x

Where is the variability in Where is the variability in the AGA7 the AGA7 Equation relative Equation relative to Composition?to Composition?Where is the variability in Where is the variability in the AGA7 the AGA7 Equation relative Equation relative to Composition?to Composition?

ACFSCF bbf ZTP x x x ACFSCFffb ZTP

x x x

How much does Zb vary with composition?

How much does Zf vary with composition?

How much does Compressibility Vary?How much does Compressibility Vary?(Base Conditions)(Base Conditions)How much does Compressibility Vary?How much does Compressibility Vary?(Base Conditions)(Base Conditions)

Compressibility VarianceBase Pressure

0.9500

1.0000

ty (Z

) AmarilloGulf Coast

0.8500

0.9000

ompr

essi

bilit Ekofisk

High CO2 N2High N2Methane

0.7500

0.8000

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

Co Air

14 114

214

314

414

514

614

714

814

914

1014

1114

1214

1314

1414

Pressure (psia)

Potential Error due to Compressibility Potential Error due to Compressibility Variation @ Base Conditions Variation @ Base Conditions (Natural Gas Mixtures)(Natural Gas Mixtures)

Potential Error due to Compressibility Potential Error due to Compressibility Variation @ Base Conditions Variation @ Base Conditions (Natural Gas Mixtures)(Natural Gas Mixtures)

Potential Error due to Compressibility Variation(Natural Gas Mixtures)

10.00%

12.00%

Potential Error

4.00%

6.00%

8.00%

Erro

r

Potential ErrorCompressibility

0.00%

2.00%

14 1421

431

441

451

461

471

481

491

4014 14 214 314 41414 11 21 31 41 51 61 71 81 91 10

111

112

113

114

1

Pressure (psia)Base Pressure

Turbine Turbine -- DesignDesignTurbine Turbine -- DesignDesign

Turbine Turbine –– Meter TubeMeter TubeTurbine Turbine –– Meter TubeMeter Tube

Turbine Turbine –– Meter Tube (Short Coupled)Meter Tube (Short Coupled)Turbine Turbine –– Meter Tube (Short Coupled)Meter Tube (Short Coupled)

Integral Flow Conditioning on Nosecone

Turbine Turbine –– Meter Tube (Close Coupled)Meter Tube (Close Coupled)Turbine Turbine –– Meter Tube (Close Coupled)Meter Tube (Close Coupled)

Integral Flow Conditioning on Nosecone

Turbine Turbine –– Calibration IssuesCalibration IssuesTurbine Turbine –– Calibration IssuesCalibration Issues Turbine

meters should be calibrated at flow density or at flowing Reynolds yNumbers

If a turbine meter is

li d t

3%

applied at a pressure higher than calibration

thpressure the meter will over-register

VD

Re

Turbine Turbine –– Calibration @ Atmospheric?Calibration @ Atmospheric?Turbine Turbine –– Calibration @ Atmospheric?Calibration @ Atmospheric?

Lab Calibration Data Lab Calibration Data ExampleExampleLab Calibration Data Lab Calibration Data ExampleExample

Turbine Turbine –– Advantages & DisadvantagesAdvantages & DisadvantagesTurbine Turbine –– Advantages & DisadvantagesAdvantages & Disadvantages

Advantages DisadvantagesGood accuracy over linear flow range High OpEXMedium Accuracy + 1% Not fully accepted by industryMedium Accuracy + 1% Not fully accepted by industryElectrical & Mechanical Output Can not tolerate dirty processesVolumetric meter Over-range = Damage = under registrationMedium installation cost Flow calibration required at operating density or

Reynolds NumberReynolds NumberMedium rangeability at high pressure Requires OilHigh Repeatability Moving parts (wear)Low to no power required Over-registration & damage w/pulsations

(Calibration Regulation Process)(Calibration, Regulation, Process)Damaged by surging flowsMedium to High Pressure DropWet Calibration RequiredWet Calibration Required

Rotary Meters Rotary Meters –– Theory of OperationTheory of OperationRotary Meters Rotary Meters –– Theory of OperationTheory of Operation

ANSI B109.3 for Rotary-Type Gas Displacement MetersDisplacement MetersPublished 2000

ACFSCF bbf ZTP xx ACFSCFffb

bbf

ZTPZTP x

x x x x

PD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor EffectsPD Meter Factor Effects Slippage establishes

performance curve and driven by

Accuracy Curve

y– Mechanical DP (bearing

friction)• Dominant at Low FlowDominant at Low Flow

– Hydraulic DP (flow, density, viscosity)

• Dominant at High Flow• Dominant at High Flow

Mechanical Clearance – Coatings and Deposits

Debris

• Deposits reduce clearances

• Cause significant changes in meter factor

• Debris abrasion

Rotary Rotary –– Advantage & DisadvantageAdvantage & DisadvantageRotary Rotary –– Advantage & DisadvantageAdvantage & Disadvantage

Advantages DisadvantagesNo upstream piping concerns High OpEXMedium Accuracy + 1% Not fully accepted by industryHigh Rangeability (50:1) Can not handle dirty processesHigh Repeatability Over-range = Damage = under registration/lock-upMedium pressure drop Flow calibration requiredMechanical Output Requires OilVolumetric meter Moving parts (wear)Low installation cost Over-registration & damage w/pulsations

(Calibration, Regulation, Process)Low to no power required Potential service interruptionNo flow profile concerns Mechanical index drag

Ultrasonic Meters Ultrasonic Meters –– AGA9AGA9Ultrasonic Meters Ultrasonic Meters –– AGA9AGA9

Ultrasonic Gas Metering Recommended Practice

Revised April 2007

Significant ChangeSignificant Change

Piping/flow conditioning guidance and profile diagnostics

Performance Based Performance Based Specification

Ultrasonic Ultrasonic –– Theory of OperationTheory of OperationUltrasonic Ultrasonic –– Theory of OperationTheory of Operation

1221

2

2 TTTT

XLV

XTransducer 2

12212 TTX

LFlow D

Transducer 1

Ultrasonic Ultrasonic –– Flow ProfileFlow ProfileUltrasonic Ultrasonic –– Flow ProfileFlow Profile

AB

CCD

Ultrasonic Ultrasonic -- Theory of OperationTheory of OperationUltrasonic Ultrasonic -- Theory of OperationTheory of Operation

• Measure transit times

C l l t i di id l h d• Calculate individual chord velocities

Weight A = 0.1382

1221

12212

t. t t- t

. X 2L V

• Weight chord velocities

• Calculate average flow velocity

4

)( WVV

Weight A 0.1382Weight B = 0.3618Weight C = 0.3618Weight D = 0.1382

g y

• Calculate average volume flow rate

1

)(i

iii WrVV

2DVQ

4.VQ i

ACFSCF bbf ZTP xx ACFSCFffb

bbf

ZTPZTP x

x x x x

Ultrasonic Ultrasonic –– Meter TubeMeter TubeUltrasonic Ultrasonic –– Meter TubeMeter Tube

Daniel USM Gas Calibration (10 point)Daniel USM Gas Calibration (10 point)Daniel USM Gas Calibration (10 point)Daniel USM Gas Calibration (10 point)

All gas ultrasonic meters require a lab calibration

Ultrasonic Ultrasonic –– Advantages & DisadvantagesAdvantages & DisadvantagesUltrasonic Ultrasonic –– Advantages & DisadvantagesAdvantages & Disadvantages

Advantages DisadvantagesLinear Meter Power RequiredHigh Accuracy + 0 25% Medium Pressure Drop w/flow conditionerHigh Accuracy + 0.25% Medium Pressure Drop w/flow conditionerVolumetric meter Can not tolerate dirty processesNo moving parts Over-range = loss of measurmentHigh rangeability Possible Pulsation Error (Calibration,

Regulation Process)Regulation, Process)High Repeatability Medium Dirty Process TolerancePower requirement Profile SensativeNo size limitation Wet Calibration Required

Low pressure drop w/o flow conditioner Susceptible to valve noiseLow OpEx High CapExField meter verification

Diagnostic Capability

AGA Report No. 11 / API MPMS Ch. 14.9Measurement of Natural Gas by Coriolis MeterAGA Report No. 11 / API MPMS Ch. 14.9Measurement of Natural Gas by Coriolis MeterMeasurement of Natural Gas by Coriolis MeterMeasurement of Natural Gas by Coriolis Meter

2nd Edition Published February 2013 Covers all single phase

natural gases as pure or a mixture of hydrocarbons and diluents

API Standard API MPMS Chapter 14.9

Recommended Practice Recommended Practice Specification, calibration,

installation, operation, maintenance, and verification,

Coriolis Measurement StandardsCoriolis Measurement Standardsfor the Natural Gas Industryfor the Natural Gas IndustryCoriolis Measurement StandardsCoriolis Measurement Standardsfor the Natural Gas Industryfor the Natural Gas Industryyyyy

AGA11 & API 14 9Coriolis Gas Industry and International Standards

AGA11 & API 14.9

ASME MFC-11-2006

AGA6

ISO 10790 ISO 10790

OMIL R137

Theory of operationTheory of operation -- Bent Tube Meter DesignBent Tube Meter DesignTheory of operationTheory of operation -- Bent Tube Meter DesignBent Tube Meter Design

Theory of Operation Theory of Operation –– Pickoff SignalsPickoff SignalsNo Flow (Top View)No Flow (Top View)

Theory of Operation Theory of Operation –– Pickoff SignalsPickoff SignalsNo Flow (Top View)No Flow (Top View)

Zero StabilityZero Stability

Coriolis Flow PerformanceCoriolis Flow PerformanceZero StabilityZero StabilityCoriolis Flow PerformanceCoriolis Flow PerformanceZero StabilityZero Stability

2.00HC3 Performance w/Zero Stability

1.00

1.50

0.00

0.50

Erro

r %

-1.00

-0.50

E

-2.00

-1.50

MMCFD

Theory of Operation Theory of Operation –– Pickoff SignalsPickoff SignalsFlow (Top View)Flow (Top View)

Theory of Operation Theory of Operation –– Pickoff SignalsPickoff SignalsFlow (Top View)Flow (Top View)

Coriolis Accuracy Specification Coriolis Accuracy Specification ––Zero Stability and Flat SpecZero Stability and Flat SpecCoriolis Accuracy Specification Coriolis Accuracy Specification ––Zero Stability and Flat SpecZero Stability and Flat Spec

HC3 Performance w/Zero Stability & Flat SpecExample

Calculation of Qt

1.00

1.50

2.00

hrtonsQhrkgQ

FlatSpecityZeroStabilQ

t

t

t

0035.0/)/(136.0%35.0/)/(4.136

/

HC3

0 50

0.00

0.50

1.00

Erro

r %

hrtonsQt /39

-1.50

-1.00

-0.50

-2.00tons/Hr

Direct Density MeasurementDirect Density MeasurementDirect Density MeasurementDirect Density MeasurementDirect Density MeasurementDirect Density MeasurementDirect Density MeasurementDirect Density MeasurementDensity measurement is based on the natural frequency

– As the mass increases, the natural frequency of the system ddecreases.

– As the mass decreases, the natural frequency of the system increases.

Tube period decreases Tube period increases

Theory of Operation Theory of Operation -- DensityDensityTheory of Operation Theory of Operation -- DensityDensityy py p yyy py p yy Density calibration is performed at the factory on air and water.

– Tube period of air (K1) 10484– Tube period of water (K2) 10966Tube period of water (K2) 10966– Density of air (D1) 0.0010– Density of water (D2) 0.9982– Temperature coefficient 4.39

Th t itt t ti ll f

Tube Period = 10817Density = 0.6871 g/cm3

The transmitter automatically performsa calculation based upon the data pointsstored in its memory during calibration.

Field calibrations can also be performed Field calibrations can also be performedusing air, water, or alternate fluidsdepending on the density span desired.

Theory of Operation Theory of Operation –– Density & Pickoff SignalDensity & Pickoff SignalTheory of Operation Theory of Operation –– Density & Pickoff SignalDensity & Pickoff Signaly py p y gy gy py p y gy g

• Density Accuracy +/- 0.0005 gm/cc

• Water Density = 1 gm/cc (potential error = 0.05%)

Natural Gas Density @• Natural Gas Density @ 500 psi = 0.0272 gm/cc (potential error 1.8%)

Coriolis Coriolis –– Theory of Operation (Pressure)Theory of Operation (Pressure)Coriolis Coriolis –– Theory of Operation (Pressure)Theory of Operation (Pressure)Flow Pressure Effect: The linear change in sensor’s indicated flow due to the

change in internal pressure on the flow tube

F Series

Elite Series

Coriolis Coriolis -- Flow Flow Pressure Pressure EffectEffectCoriolis Coriolis -- Flow Flow Pressure Pressure EffectEffect

Potential Error w/o Pressure Correction(Natural Gas)

Coriolis AttributesCoriolis AttributesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve InitiativesCoriolis AttributesCoriolis AttributesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve InitiativesHelp Gas Industry Achieve Initiatives

Calibration directly transfers across fluid range

Reynolds Number

– Calibration independent of fluid phase

– Reduced meter flow calibration and verification costs

Asymmetrical Profile

costs

Reduction in measurement uncertainty caused by field operating conditions

A c tu a l v e lo c ity

Swirl

– No flow conditioning or special piping requirements

• Insensitive to profile change

High immunity to errors and damage due to flowPulsating Flow

– High immunity to errors and damage due to flow surges, pulsations, and flow turbulence / noise

– Reduction in measurement uncertainty due to process condition and fluid composition variability

Coriolis Coriolis –– Standard Volume CalculationsStandard Volume CalculationsCoriolis Coriolis –– Standard Volume CalculationsStandard Volume Calculations

PFMassSCF P

FMassSCF

b

PF

TbRZbMrPb

MassSCF

xx(Gas) x

AGA8 Detail

PFMassSCF

TbRZb

x x

AGA8 Gross 1 or 2P

(Air)(Gas)x Gr

AGA11 AGA11 -- Installation Best PracticesInstallation Best PracticesPiping Alignment and SupportPiping Alignment and SupportAGA11 AGA11 -- Installation Best PracticesInstallation Best PracticesPiping Alignment and SupportPiping Alignment and Support• Proper weight support

• No sagging pipesPiping supports installed near• Piping supports installed near upstream and downstream flanges of meter

• Meter flow tube case isMeter flow tube case is sacred ground• Case should not be used to

support the meter or other equipment

• Proper alignment of piping & flanges• Use of fabrication spool piece

when fabricating piping in the field (slip-fit desired)

AGA11 AGA11 -- Installation Best PracticesInstallation Best PracticesOrientation & Piping Requirements (Gas)Orientation & Piping Requirements (Gas)AGA11 AGA11 -- Installation Best PracticesInstallation Best PracticesOrientation & Piping Requirements (Gas)Orientation & Piping Requirements (Gas)

• No special upstream or downstream piping requirements

• Flow Tubes up on gas preferred

• Flow Tubes in flag position with flow direction down preferredflow direction down preferred (WET GAS!!!)

Coriolis Coriolis –– Advantage & DisadvantageAdvantage & DisadvantageCoriolis Coriolis –– Advantage & DisadvantageAdvantage & Disadvantage

Advantages DisadvantagesNo upstream piping concerns Power RequiredHigh Accuracy + 0.25% Not fully accepted by industryHigh Rangeability @ HP (50:1) Not a volumetric technologyHigh Reproducibility Medium to high pressure dropField meter verification Medium repeatabilityWater calibration Xfers to gas Loss of turndown in low pressures < 100 psi(High immunity to pulsation errorHigh immunity to dirty processesLow installation costNo over-rangeLow OpEx

Process & Performance DiagnosticsDiagnosticsNo wearing parts