seccion 2. revision de aga 9 ppt

8/10/2019 Seccion 2. Revision de AGA 9 Ppt

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Section 2.

Overview of Industry

Recommendations at CustodyTransfer Applications


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Measurement of Gas by

Multipath Ultrasonic Meters

Transmission Measurement CommitteeReport No. 9

Copyright 1998 American Gas Association

All Rights Reserved

Operating Section

American Gas Association

1515 Wilson Boulevard

Arlington, Virginia 22209

U.S.A.

Catalog No. XQ9801

June 1998

ISO / WD 17089

Guides and Standards


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!Advantage and Disadvantages of the USM

! The Operational Range of an USM

! Typical Meter Performance at the Laboratory! Pulsation, vibration and Flow Distortion

Effects?

! Line Pressure Effects on Meter Performance

! Temperature Influence on Meter Performance

What are :

Frequent Asked Questions


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+ Largest Rangeability in the Industry

+ Good Repeatability and Linearity

+ Large Volumetric Capacity

+ Widely Used for Custody TransferApplications

+ Large Volume of Information Available to

Evaluate Meter Performance

+ Meter Fingerprint during Commissioning

produce info to Track Meter Performance

Advantages and Disadvantages


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"Gas Sourness can Affect Meter Performance

"More Expensive than Other Technologies

"Accuracy affected by entrained liquids in thegas

" Sensitivity to noise, installation network and

pressure and volume control accessories

Advantages and Disadvantages


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! Maximum Velocity limited by MeterCharacteristics and Station Design

! Minimum Velocity Determined by RequiredAccuracy

Operational Range


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Pressure Effects

A minimum gas density ( function ofpressure) is required by the ultrasonictransducers to ensure acoustic coupling ofthe sound pulses to and from the gas

(Both AGA 9 and ISO agrees on minimum

operating pressure to be specified)


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Pipe Reynolds number

1e+5 1e+6 1e+7

(Q

meter-

Qfacility

)/Qfacility

[%]

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4Ultrasonic Meter

Pressure 3Pressure 2Pressure 1

all facilities y = .1856 + 321.6/x.5

Facility E y = .1356 + 303.4/x.5

Facility E +/- 2!(.186)

Testing of 8 ultrasonic meter: Facility 1(P1=2270 kPa, P2=4750 kPa, P3=6300 kPa).

Line Pressure Variation Effects on a 8-inch USM

HP calibration of 8-inch meter

to sonic nozzles. Sep.1999


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Pipe Reynolds number

1e+5 1e+6 1e+7

(Qmeter-

Qfacility

)/Qfacility

[%]

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4Ultrasonic Meter

Pressure 2Pressure 1

all facilities y = .1856 + 321.6/x.5

Facility C y = -5.3 + 9.5/x.034

Facility C +/- 2!(.195)

Testing of 8 ultrasonic meter: Facility 2(P1=2100 kPa, P2=3500 kPa).

HP calibration of 8-inch meterto turbine meters June.1999

Line Pressure Variation Effects on a 8-inch USM


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Content of AGA 9

!

Operating Conditions! Meter Requirements

! Performance Requirements

! Individual Meter Testing Requirements

! Installation Requirements

! Field Verification test


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! Densities between 0.554 and 0.87

! Acoustic wave attenuated by sour gas

! Flowing gas and operating ambient temperature

of 25 oC to +55 oC! Operation within Qmin ,q transition, qmax! Upstream piping may affect gas velocity profile

Operating Conditions


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! Meters MDOP lower of body, flanges andtransducer connections/assemblies MDOP

! Standard overall face to face length for eachflange class and diameter

! Upstream pipe and UM bore to within 1% of

each other

Meter Requirements


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! Replacement or transducer relocation should

not affect meter performance! SPU operating over operation conditions

within meter performance specs.

! SPU replacement maintaining meterperformance specs.

!

Minimum NEC Class I, Div 2, Group D,Hazardous Area

Meter Requirements


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! Local or remote capability for configuring

SPU and monitoring of the operation! Minimum diagnostic measurement via

serial interface (RS-232 ot RS-485)

(Seccion 4.5.5)! Configuration Parameters used by the SPU

should be password protected

! Documentation on accuracy, installationeffects, electronics, transducers and zero-

flow verification ( See AGA 9 seccion 4.6)

Meter Requirements


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Repeatability : 0.2% for qt qi qmax0.4% for qmin qi< qt

Resolution : 0.003 ft/s (0.001 m/s)

Velocity sampling interval : 1 second

Maximum Peak-to-PeakError

(see Figure 1)

: 0.7% for qt qi qmax

Zero flow reading :


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Maximum Error(see Figure 1)

: 1.0% for qt qi qmax1.4% for qmin qi< qt

Accuracy for Meters < 12 inch NPS

Maximum Error(see Figure 1)

: 0.7% for qt qi qmax1.4% for qmin qi< qt

Performance Requirements

Accuracy for Meters >= 12 inch NPS


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Meter Performance Summary

Flow Rate (qi)

-1.6

-1.4-1.2

-1.0

-0.8

-0.6

-0.4

-0.2-0.0

0.2

0.4

0.6

0.8

1.01.2

1.4

1.6

Percen

tError

qmin qmaxqt

Repeatability "0.2% (qi$

qt)

Large meter error limit +0.7%

Large meter error limit -0.7%

Small meter error limit +1.0%

Small meter error limit -1.0%

Expanded error limit +1.4% (qi


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Individual Meter Testing

! Dimensional Measurement (internal ID,length of each acoustic path, axial distance)

! Zero-Flow Verification Test

! Flow Calibration Test

! Calibration Factor Adjustment


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Zero Flow Verification Test

# Purpose: To verify the transit timecalculations

# Requirements: well known acoustic properties

of test gas, and stabilized pressure and

temperature conditions# Calculations: Mean gas velocity and SD for

each acoustic path, per path and average

SOS values

# Results: if necessary, a zero flow offset factor


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Flow Calibration Test

# Purpose: Evaluate Meter performance undercontrolled operational conditions

# Requirements: a flow calibration facility,

traceable to national/international standards,parameters calculation based on AGA 8 andtraceable to NIST

# Flow Conditioning: The decision to use a FC isleft up to the manufacturer


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!

Calibration Factor! Per path Velocity of Sound Correlation

! velocity Determined by Required Accuracy

Calibration Factors for 12" USM

0.9900

0.9950

1.0000

1.0050

1.0100

1.0150

0 1 2 3 4

Flow Conditioner type

Adjustmentfactors

No FC

FC #2

FC#1

Positive adjustment

Meter Negative Reading

Flow Conditioning Effects


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Calibration Factor Adjustment

# Purpose: Minimize the measurementuncertainty of a multi-path ultrasonic meter.Appendix A

# Methodology:AGA Flow-Weighted mean erroror a more sophisticated error correctionscheme over the meters range of flow rates.

Example 1. Example 2.


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Installation Requirements

! Environment

! Piping Configurations

! Associated Flow Computer! Maintenance


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Field Verification Test

! Zero Flow Verification Test! VOS analysis

! Individual Path Measurement Analysis

! Internal Inspection

! Meter Reported VOS versus Calculated VOS

from AGA 8


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Meter Recalibration

!AGA does not address USM recalibration

! ISO is proposing a chapter

seccion 2. revision de aga 9 ppt

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