ISO 21903:2020
(Main)Refrigerated hydrocarbon fluids — Dynamic measurement — Requirements and guidelines for the calibration and installation of flowmeters used for liquefied natural gas (LNG) and other refrigerated hydrocarbon fluids
Refrigerated hydrocarbon fluids — Dynamic measurement — Requirements and guidelines for the calibration and installation of flowmeters used for liquefied natural gas (LNG) and other refrigerated hydrocarbon fluids
This document specifies the metrological and technical requirements for flowmeters intended to be used for the dynamic measurement of liquefied natural gas (LNG) and other refrigerated hydrocarbon fluids. For LNG static volume measurement used in custody transfer, see ISO 10976. This document sets the best practice for the proper selection and installation of flowmeters in cryogenic applications and identifies the specific issues that can affect the performance of the flowmeter in use. Moreover, it offers a calibration guideline for laboratory and on-site conditions (mass or volume) by either using LNG or other reference fluids. The choice of calibration fluid will depend on the capabilities of the available flow calibration facilities and the ability to achieve the required overall measurement uncertainty demanded by the intended application. This document is applicable, but is not limited, to the use of Coriolis and ultrasonic flowmeters for dynamic measurements of LNG. In principle, LNG and other refrigerated liquid hydrocarbons are considered in this document. Recommendations in this document are based on the available test results with LNG. These results are probably applicable to other cryogenic fluids.
Hydrocarbures liquides réfrigérés — Mesurage dynamique — Exigences et lignes directrices pour l’étalonnage et l’installation de débitmètres utilisés pour le gaz naturel liquéfié (GNL) et autres hydrocarbures liquides réfrigérés
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INTERNATIONAL ISO
STANDARD 21903
First edition
2020-02
Refrigerated hydrocarbon
fluids — Dynamic measurement —
Requirements and guidelines for
the calibration and installation of
flowmeters used for liquefied natural
gas (LNG) and other refrigerated
hydrocarbon fluids
Hydrocarbures liquides réfrigérés — Mesurage dynamique —
Exigences et lignes directrices pour l’étalonnage et l’installation
de débitmètres utilisés pour le gaz naturel liquéfié (GNL) et autres
hydrocarbures liquides réfrigérés
Reference number
©
ISO 2020
ISO 21903:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
ISO 21903:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 3
4 Flowmeter selection . 3
4.1 Considerations of meters specific to LNG metering. 3
4.2 Coriolis flowmeter . 4
4.3 Ultrasonic flowmeter . 4
5 Process conditions . 5
5.1 Temperature effects . 5
5.1.1 Loading procedures. 5
5.1.2 Temperature effects on CMF measurements . 5
5.1.3 Temperature effects on USM measurements. 6
5.2 Pressure effects . 6
5.2.1 Coriolis flowmeter . 6
5.2.2 Ultrasonic flowmeter . 7
5.3 Mechanical vibrations . 7
5.3.1 Coriolis flowmeter . 7
5.3.2 Ultrasonic flowmeter . 8
5.4 Cavitation . 8
5.4.1 Coriolis flowmeter . 8
5.4.2 Ultrasonic flowmeter . 9
5.5 Thermodynamic properties of LNG . 9
6 Installation . 9
6.1 Valves . 9
6.2 Swirl and non-uniform profiles . 9
6.2.1 Coriolis flowmeter . 9
6.2.2 Ultrasonic flowmeter .10
6.3 Flow conditioners .10
6.4 Pipe stress and torsion .10
6.4.1 Coriolis flowmeter .10
6.4.2 Ultrasonic flowmeter .11
6.5 Flowmeter installation recommendations .11
6.5.1 Coriolis flowmeter .11
6.5.2 Ultrasonic flowmeter .12
6.6 Crosstalk and sensitivity to noise .12
6.6.1 Coriolis flowmeter .12
6.6.2 Ultrasonic flowmeter .12
6.7 Zero offset — Verification and adjustment procedures .13
6.7.1 Coriolis flowmeter .13
6.7.2 Ultrasonic flowmeter .15
6.8 Temperature management .15
6.8.1 Thermal insulation .15
6.8.2 Cooling procedure .16
6.8.3 Warming procedure .17
7 Calibration .18
7.1 General considerations .18
7.2 Calibration in a laboratory .18
7.2.1 Gravimetric method .18
ISO 21903:2020(E)
7.2.2 Master meter method .20
7.3 Calibration in situ .22
7.3.1 Gravimetric method using a weighbridge .22
7.3.2 Road tanker temporarily on weighbridge .23
7.3.3 Measurement uncertainty .23
7.4 Interconnected pipe volume .23
Annex A (informative) Working principle Coriolis flowmeter .27
Annex B (informative) Working principle of the ultrasonic flowmeter .30
Annex C (normative) Hardware for an LNG calibration facility .33
Annex D (informative) Examples of calibration data .36
Annex E (normative) Alternative calibration procedure based on alternative liquids .39
Annex F (informative) Thermodynamic properties of LNG .41
Bibliography .47
iv © ISO 2020 – All rights reserved
ISO 21903:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ p
...
INTERNATIONAL ISO
STANDARD 21903
First edition
2020-02
Refrigerated hydrocarbon
fluids — Dynamic measurement —
Requirements and guidelines for
the calibration and installation of
flowmeters used for liquefied natural
gas (LNG) and other refrigerated
hydrocarbon fluids
Hydrocarbures liquides réfrigérés — Mesurage dynamique —
Exigences et lignes directrices pour l’étalonnage et l’installation
de débitmètres utilisés pour le gaz naturel liquéfié (GNL) et autres
hydrocarbures liquides réfrigérés
Reference number
©
ISO 2020
ISO 21903:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
ISO 21903:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Abbreviated terms . 3
4 Flowmeter selection . 3
4.1 Considerations of meters specific to LNG metering. 3
4.2 Coriolis flowmeter . 4
4.3 Ultrasonic flowmeter . 4
5 Process conditions . 5
5.1 Temperature effects . 5
5.1.1 Loading procedures. 5
5.1.2 Temperature effects on CMF measurements . 5
5.1.3 Temperature effects on USM measurements. 6
5.2 Pressure effects . 6
5.2.1 Coriolis flowmeter . 6
5.2.2 Ultrasonic flowmeter . 7
5.3 Mechanical vibrations . 7
5.3.1 Coriolis flowmeter . 7
5.3.2 Ultrasonic flowmeter . 8
5.4 Cavitation . 8
5.4.1 Coriolis flowmeter . 8
5.4.2 Ultrasonic flowmeter . 9
5.5 Thermodynamic properties of LNG . 9
6 Installation . 9
6.1 Valves . 9
6.2 Swirl and non-uniform profiles . 9
6.2.1 Coriolis flowmeter . 9
6.2.2 Ultrasonic flowmeter .10
6.3 Flow conditioners .10
6.4 Pipe stress and torsion .10
6.4.1 Coriolis flowmeter .10
6.4.2 Ultrasonic flowmeter .11
6.5 Flowmeter installation recommendations .11
6.5.1 Coriolis flowmeter .11
6.5.2 Ultrasonic flowmeter .12
6.6 Crosstalk and sensitivity to noise .12
6.6.1 Coriolis flowmeter .12
6.6.2 Ultrasonic flowmeter .12
6.7 Zero offset — Verification and adjustment procedures .13
6.7.1 Coriolis flowmeter .13
6.7.2 Ultrasonic flowmeter .15
6.8 Temperature management .15
6.8.1 Thermal insulation .15
6.8.2 Cooling procedure .16
6.8.3 Warming procedure .17
7 Calibration .18
7.1 General considerations .18
7.2 Calibration in a laboratory .18
7.2.1 Gravimetric method .18
ISO 21903:2020(E)
7.2.2 Master meter method .20
7.3 Calibration in situ .22
7.3.1 Gravimetric method using a weighbridge .22
7.3.2 Road tanker temporarily on weighbridge .23
7.3.3 Measurement uncertainty .23
7.4 Interconnected pipe volume .23
Annex A (informative) Working principle Coriolis flowmeter .27
Annex B (informative) Working principle of the ultrasonic flowmeter .30
Annex C (normative) Hardware for an LNG calibration facility .33
Annex D (informative) Examples of calibration data .36
Annex E (normative) Alternative calibration procedure based on alternative liquids .39
Annex F (informative) Thermodynamic properties of LNG .41
Bibliography .47
iv © ISO 2020 – All rights reserved
ISO 21903:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ p
...
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