SIST EN ISO 7278-2:2023

Petroleum measurement systems - Part 2: Pipe prover design, calibration and operation (ISO 7278-2:2022)

This document provides descriptions of the different types of pipe provers, otherwise known as displacement provers, currently in use. These include sphere (ball) provers and piston provers operating in unidirectional and bidirectional forms. It applies to provers operated in conventional, reduced volume, and small volume modes.
This document gives guidelines for:
—    the design of pipe provers of each type;
—    the calibration methods;
—    the installation and use of pipe provers of each type;
—    the interaction between pipe provers and different types of flowmeters;
—    the calculations used to derive the volumes of liquid measured (see Annex A);
—    the expected acceptance criteria for fiscal and custody transfer applications, given as guidance for both the calibration of pipe provers and when proving flowmeters (see Annex C).
This document is applicable to the use of pipe provers for crude oils and light hydrocarbon products which are liquid at ambient conditions. The principles apply across applications for a wider range of liquids, including water. The principles also apply for low vapour pressure, chilled and cryogenic products, however use with these products can require additional guidance.

Flüssige Kohlenwasserstoffe - Dynamische Messung - Prüfsysteme für volumetrische Messgeräte - Teil 2: Rohrprüfer (ISO 7278-2:2022)

Dieses Dokument enthält Beschreibungen der verschiedenen zur Zeit verwendeten Arten von Rohrprüfern; diese werden auch als Verdrängungsprüfer bezeichnet. Dazu gehören Kugelprüfer und Kolbenprüfer, die entweder unidirektional oder bidirektional betrieben werden. Es gilt für Prüfer, die entweder in herkömmlicher Weise oder in Betriebsarten für reduzierte Volumina oder kleine Volumina betrieben werden.
Dieses Dokument enthält Leitlinien für:
—   die Auslegung von Rohrprüfern jedes der einzelnen Typen;
—   die Kalibrierverfahren;
—   die Installation und die Verwendung von Rohrprüfern jedes der einzelnen Typen;
—   die Wechselwirkung zwischen Rohrprüfern und verschiedenen Arten von Durchflussmessgeräten;
—   die Berechnungen zur Ableitung der gemessenen Flüssigkeitsvolumina (siehe Anhang A);
—   die für fiskalische und eichpflichtige Verkehrsanwendungen erwarteten Annahmekriterien, angegeben als Leitlinien sowohl für die Kalibrierung von Rohrprüfern als auch für die Prüfung von Durchflussmessgeräten (siehe Anhang C).
Dieses Dokument ist anzuwenden für die Verwendung von Rohrprüfern für Rohöle und leichte Kohlenwasserstoffprodukte, die bei Umgebungsbedingungen flüssig sind. Die hierin angegebenen Grundsätze gelten auch für Anwendungen mit weiteren Flüssigkeiten, einschließlich Wasser. Die Grundsätze gelten auch für Produkte mit niedrigem Dampfdruck sowie gekühlte und tiefkalte Produkte, jedoch kann die Verwendung mit diesen Produkten zusätzliche Leitlinien erfordern.

Systèmes de mesurage des produits pétroliers - Partie 2: Conception, étalonnage et fonctionnement des tubes étalons (ISO 7278-2:2022)

Le présent document décrit les différents types de tubes étalons, également appelés “étalons à déplacement”, actuellement utilisés. Cela comprend les tubes étalons à sphère et à piston, fonctionnant de manière unidirectionnelle et bidirectionnelle. Le présent document s'applique aux tubes étalons fonctionnant en mode conventionnel, à volume réduit et à petit volume.
Le présent document fournit des lignes directrices concernant:
—    la conception des tubes étalons de chaque type;
—    les méthodes d'étalonnage;
—    l'installation et l'utilisation des tubes étalons de chaque type;
—    l'interaction entre les tubes étalons et différents types de débitmètres;
—    les calculs utilisés pour obtenir les volumes de liquide mesurés (voir l'Annexe A);
—    les critères d'acceptation attendus pour les applications fiscales et de transactions commerciales, donnés à titre de recommandation, à la fois pour l'étalonnage des tubes étalons et la vérification des débitmètres (voir l'Annexe C).
Le présent document s'applique à l'utilisation de tubes étalons pour le pétrole brut et les produits d'hydrocarbure légers qui sont à l'état liquide dans les conditions ambiantes. Les principes cités s'appliquent à différentes applications ayant recours à un éventail plus large de liquides, y compris l'eau. Ces principes s'appliquent également aux produits à faible pression de vapeur, ainsi qu'aux produits refroidis et cryogéniques. Toutefois, l'utilisation de ces produits peut nécessiter des recommandations supplémentaires.

Merilni sistemi za nafto - 2. del: Načrtovanje, kalibracija in delovanje merilnika cevi (ISO 7278-2:2022)

Ta dokument podaja opise različnih merilnikov cevi (znanih tudi kot merilniki premika), ki so trenutno v uporabi. To vključuje kroglične in batne merilnike z enosmernim oziroma dvosmernim delovanjem. Uporablja se za merilnike, ki delujejo v običajnem načinu, načinu z zmanjšano in majhno prostornino.
Ta dokument podaja smernice za:
– načrtovanje merilnikov cevi posamezne vrste;
– kalibracijske metode;
– namestitev in uporabo merilnikov cevi posamezne vrste;
– medsebojno delovanje merilnikov cevi in različnih vrst merilnikov pretoka;
– izračune, ki se uporabljajo za izpeljavo izmerjene prostornine tekočine (glej dodatek A);
– pričakovane kriterije sprejemljivosti za fiskalni prenos in prenos skrbništva, podane kot smernice za kalibracijo merilnikov cevi in preskušanje merilnikov pretoka (glej dodatek C).
Ta dokument je namenjen za uporabo merilnikov cevi za surovo nafto in izdelke iz lahkega ogljikovodika, ki so pri običajnih okoljskih pogojih v tekočem stanju. Načela se uporabljajo za različne vrste tekočin, vključno z vodo. Prav tako se uporabljajo za izdelke z nizkim parnim tlakom ter ohlajene in kriogene izdelke, vendar so lahko pri takšni uporabi potrebne dodatne smernice.

General Information

• Status: Published
• Public Enquiry End Date: 31-Jan-2022
• Publication Date: 27-Dec-2022
• ICS: 75.180.30 - Volumetric equipment and measurements
• Technical Committee: NAD - Petroleum products, lubricants and related products
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 14-Dec-2022
• Due Date: 18-Feb-2023
• Completion Date: 28-Dec-2022
• Ref Project: EN ISO 7278-2:2022 - Petroleum measurement systems - Part 2: Pipe prover design, calibration and operation (ISO 7278-2:2022)

Relations

• Replaces: SIST EN ISO 7278-2:1998 - Liquid hydrocarbons - Dynamic measurement - Proving systems for volumetric meters - Part 2: Pipe provers (ISO 7278-2:1988)
• Effective Date: 01-Feb-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 7278-2:2023
01-februar-2023
Nadomešča:
SIST EN ISO 7278-2:1998
Merilni sistemi za nafto - 2. del: Načrtovanje, kalibracija in delovanje merilnika cevi
(ISO 7278-2:2022)
Petroleum measurement systems - Part 2: Pipe prover design, calibration and operation
(ISO 7278-2:2022)
Flüssige Kohlenwasserstoffe - Dynamische Messung - Prüfsysteme für volumetrische
Messgeräte - Teil 2: Rohrprüfer (ISO 7278-2:2022)
Systèmes de mesurage des produits pétroliers - Partie 2: Conception, étalonnage et
fonctionnement des tubes étalons (ISO 7278-2:2022)
Ta slovenski standard je istoveten z: EN ISO 7278-2:2022
ICS:
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
SIST EN ISO 7278-2:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 7278-2:2023

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SIST EN ISO 7278-2:2023


EN ISO 7278-2
EUROPEAN STANDARD

NORME EUROPÉENNE

November 2022
EUROPÄISCHE NORM
ICS 75.180.30 Supersedes EN ISO 7278-2:1995
English Version

Petroleum measurement systems - Part 2: Pipe prover
design, calibration and operation (ISO 7278-2:2022)
Systèmes de mesurage des produits pétroliers - Partie Flüssige Kohlenwasserstoffe - Dynamische Messung -
2: Conception, étalonnage et fonctionnement des tubes Prüfsysteme für volumetrische Messgeräte - Teil 2:
étalons (ISO 7278-2:2022) Rohrprüfer (ISO 7278-2:2022)
This European Standard was approved by CEN on 28 October 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7278-2:2022 E
worldwide for CEN national Members.

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SIST EN ISO 7278-2:2023
EN ISO 7278-2:2022 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 7278-2:2023
EN ISO 7278-2:2022 (E)
European foreword
This document (EN ISO 7278-2:2022) has been prepared by Technical Committee ISO/TC 28
"Petroleum and related products, fuels and lubricants from natural or synthetic sources" in
collaboration with Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related
products of petroleum, synthetic and biological origin” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2023, and conflicting national standards shall be
withdrawn at the latest by May 2023.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 7278-2:1995.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 7278-2:2022 has been approved by CEN as EN ISO 7278-2:2022 without any
modification.

3

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SIST EN ISO 7278-2:2023

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SIST EN ISO 7278-2:2023
INTERNATIONAL ISO
STANDARD 7278-2
Second edition
2022-11
Petroleum measurement systems —
Part 2:
Pipe prover design, calibration and
operation
Systèmes de mesurage des produits pétroliers —
Partie 2: Conception, étalonnage et fonctionnement des tubes étalons
Reference number
ISO 7278-2:2022(E)
© ISO 2022

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SIST EN ISO 7278-2:2023
ISO 7278-2:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2022 – All rights reserved

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SIST EN ISO 7278-2:2023
ISO 7278-2:2022(E)
Contents Page
Foreword .v
Introduction . vi
1 S c op e . 1
2 Nor m at i ve r ef er enc e s . 1
3 Terms, definitions, symbols and units . 1
3.1 T erms and definitions . 1
3.2 S ymbols and units . 8
4 Design classification of pipe provers .9
4 .1 C om mon f e at u r e s . 9
4 . 2 Spher e pr over s . 11
4.2.1 General . 11
4.2.2 U nidirectional sphere provers . 11
4.2.3 Bidirectional sphere provers . 13
4 . 3 P i s t on pr over s . 15
4.3.1 G eneral .15
4.3.2 U nidirectional piston provers . 16
4.3.3 B idirectional piston provers . 16
5 Operational classification of provers .16
5.1 G eneral . 16
5 . 2 C onvent ion a l pr over . 17
5.3 R educed volume prover . 18
5.4 Small volume prover . 18
6 D e sig n .20
6.1 General considerations.20
6 . 2 P r over b a r r el . 21
6.2.1 E nd chambers (launch and receive chambers) . 21
6 . 2 . 2 R u n-i n len g t h . 22
6.2.3 P rover pipe or barrel .22
6.2.4 I nternal finish . 22
6.3 P roprietary small volume piston provers . 23
6.4 Si zing of provers . 24
6.4.1 G eneral . 24
6 .4 . 2 C a l ibr at e d volu me .25
6.4.3 Length between detectors . 25
6.4.4 Diameter and Velocity .26
6 .4 . 5 P r e s s u r e lo s s .26
6 . 5 D i s placer s . 27
6.5.1 General . 27
6 . 5 . 2 Spher e s . 27
6. 5 . 3 P i s t on s .28
6.6 D isplacer Velocity . .28
6.6.1 G eneral .28
6.6.2 Minimum velocity .28
6.6.3 Maximum velocity .29
6.7 D e t e c t or s. 29
6 . 8 P r over v a l ve s .30
6.9 Additional design considerations . 31
7 A nc i l l a r y e qu ipment .32
7.1 O verview of temperature and pressure measurement . 32
7. 2 Temp er at u r e me a s u r ement . 32
7. 3 P r e s s u r e me a s u r ement .33
7.4 C a l ibr at ion c on ne c t ion s.33
iii
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SIST EN ISO 7278-2:2023
ISO 7278-2:2022(E)
7.5 S ystem control .34
8 P u l s e i nt er p ol at ion .34
9 I n s t a l l at ion .34
9.1 Me c h a n ic a l i n s t a l l at ion.34
9.1.1 G eneral .34
9.1.2 Fixed provers . 37
9.1. 3 Mobi le pr over s . 37
9.2 E le c t r ica l i n s t a l l at ion .38
9.3 O ther installation recommendations .38
10 T r ac e abi l it y .38
11 C a l ibr at ion .40
11.1 General .40
11.2 C alibration circuits and equipment .40
11.3 W ater draw calibration method . 42
11. 3 .1 D e s c r ip t ion . 42
11.3.2 Volumetric measure as reference . 43
11.3.3 Gravimetric as reference . 45
11.4 Master meter calibration method . 47
11.5 S equential master meter method . 50
11.6 C oncurrent master meter method . 51
11.7 C a l ibr at ion pr o c e du r e s . 51
12 Operation to prove a flowmeter .52
12.1 Setting up a prover . 52
12.2 Mobile prover prior to arrival on site . 52
12.3 Mobile prover on arrival on site . 52
12 .4 St abi l i z i n g t emp er at u r e . 53
12.5 P eriodical checks of factors affecting accuracy . 53
12.6 Meter proving operation . 53
12.7 P reliminary assessment of the results . .54
12.8 F ault finding . 55
13 S a f e t y .55
13.1 G eneral . 55
13 . 2 Per m it s .56
13.3 O pening end chambers and removing a displacer .56
13.4 S pecial precautions when proving with LPG .56
13 . 5 F i r e pr e c aut ion s . 57
13.6 M iscellaneous safety precautions . 57
13.7 S afety records . 57
Annex A (informative) Calculations .59
Annex B (informative) Selecting a prover volume for a flowmeter .70
Annex C (informative) Acceptance criteria and performance specification .72
Annex D (informative) Troubleshooting .83
Annex E (informative) Sphere or detector replacement and twin pairs of detectors .89
Annex F (informative) Pulse interpolation .91
Annex G (informative) Alternative designs .95
Annex H (informative) Calibration procedures .97
Annex I (informative) Example of prover calibration certificate . 102
Bibliography . 107
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SIST EN ISO 7278-2:2023
ISO 7278-2:2022(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/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels
and lubricants from natural or synthetic sources, Subcommittee SC 2, Measurement of petroleum and
related products, in collaboration with the European Committee for Standardization (CEN) Technical
Committee CEN/TC 19 Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic
and biological origin, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This second edition cancels and replaces the first edition (ISO 7278-2:1988), which has been technically
revised. It also cancels and replaces the first edition of ISO 7278-4:1999, the content of which has been
incorporated.
The main changes are as follows:
— The content and scope now covers the design of pipe provers given in ISO 7278-2:1988 and the
guidance for operators given in ISO 7278-4:1999, which will be withdrawn.
— The different types of pipe prover designs and operating methods have been defined and described.
— The variety of operational methods and the means to apply them to flowmeter calibration of
different relative sizes has been described.
— The design, calibration and use of small volume (compact) prover designs has been included.
— The document has been changed from a normative document to a guidance document to reflect best
practices.
— The document takes into account changes in practice described in alternative standards produced
by the American Petroleum Institute (API) and the Energy Institute (EI).
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
v
© ISO 2022 – All rights reserved

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SIST EN ISO 7278-2:2023
ISO 7278-2:2022(E)
Introduction
In the petroleum industry the term “provin
...

SLOVENSKI STANDARD
oSIST prEN ISO 7278-2:2022
01-januar-2022
Merilni sistemi za nafto - 2. del: Načrtovanje, kalibracija in delovanje merilnika cevi
(ISO/DIS 7278-2:2021)
Petroleum measurement systems - Part 2: Pipe prover design, calibration and operation
(ISO/DIS 7278-2:2021)
Flüssige Kohlenwasserstoffe - Dynamische Messung - Prüfsysteme für volumetrische
Meßgeräte - Teil 2: Rohrprüfer (ISO/DIS 7278-2:2021)
Ta slovenski standard je istoveten z: prEN ISO 7278-2
ICS:
75.180.30 Oprema za merjenje Volumetric equipment and
prostornine in merjenje measurements
oSIST prEN ISO 7278-2:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 7278-2:2022

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oSIST prEN ISO 7278-2:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 7278-2
ISO/TC 28/SC 2 Secretariat: BSI
Voting begins on: Voting terminates on:
2021-11-18 2022-02-10
Petroleum measurement systems —
Part 2:
Pipe prover design, calibration and operation
ICS: 75.180.30
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 7278-2:2021(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2021

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oSIST prEN ISO 7278-2:2022
ISO/DIS 7278-2:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
  © ISO 2021 – All rights reserved

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oSIST prEN ISO 7278-2:2022
ISO/DIS 7278-2:2021(E)
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and units . 1
3.1 Terms and definitions . 1
3.2 Symbols and units . 7
4 Design classification of pipe provers .9
4.1 Common features . 9
4.2 Sphere provers . 10
4.2.1 General . 10
4.2.2 Unidirectional Sphere Provers . . 11
4.2.3 Bidirectional sphere provers .12
4.3 Piston provers . 13
4.3.1 General .13
4.3.2 Unidirectional Piston provers . 14
4.3.3 Bidirectional piston provers . 14
5 Operational classification of provers .14
5.1 General . 14
5.2 Conventional prover . 15
5.3 Reduced volume prover . 16
5.4 Small volume prover (SVP) . 16
6 Design .18
6.1 General considerations. 18
6.2 Prover barrel . 19
6.2.1 End chambers (Launch and Receive Chambers) . 19
6.2.2 Run-in length . 20
6.2.3 Prover pipe or barrel .20
6.2.4 Internal Finish .20
6.3 Small volume piston provers. 21
6.4 Sizing of provers .22
6.4.1 General .22
6.4.2 Calibrated volume .23
6.4.3 Length between detectors . 23
6.4.4 Diameter and Velocity . 24
6.4.5 Pressure loss . 24
6.5 Displacers . 25
6.5.1 General . 25
6.5.2 Spheres . 25
6.5.3 Pistons . 26
6.6 Displacer Velocity . . 26
6.6.1 General .26
6.6.2 Minimum Velocity .26
6.6.3 Maximum Velocity . 27
6.7 Detectors. 27
6.8 Prover valves .28
6.9 Additional design considerations .29
7 Ancillary equipment .30
7.1 Temperature and pressure measurement .30
7.1.1 Temperature measurement . 30
7.1.2 Pressure measurement . 31
7.2 Calibration connections. 31
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oSIST prEN ISO 7278-2:2022
ISO/DIS 7278-2:2021(E)
7.3 System control . 31
8 Pulse interpolation .32
9 Installation .32
9.1 Mechanical installation. 32
9.1.1 General . 32
9.1.2 Fixed Provers . 35
9.1.3 Mobile Provers .36
9.2 Electrical installation . 36
9.3 Other installation requirements. 36
10 Traceability .37
11 Calibration .39
11.1 General .39
11.2 Calibration Circuits and equipment . 39
11.3 Water draw calibration method . 41
11.3.1 Description . 41
11.3.2 Volumetric measure as reference . 42
11.3.3 Gravimetric as reference .44
11.4 Master meter calibration method .46
11.5 Sequential master meter method .49
11.6 Concurrent master meter method .50
11.7 Calibration procedures . 50
12 Operation to prove a flowmeter .50
12.1 Setting up a prover .50
12.1.1 Mobile prover prior to arrival on site. . 51
12.1.2 Mobile prover on arrival on site . 51
12.2 Stabilizing temperature . 51
12.3 Periodical checks of factors affecting accuracy . 52
12.4 Meter proving operation . 52
12.5 Preliminary assessment of the results . . 53
12.6 Fault finding .54
13 Safety .54
13.1 General .54
13.2 Permits . 55
13.3 Opening End Chambers and Removing a Displacer . 55
13.4 Special Precautions When Proving With LPG . 55
13.5 Fire precautions .56
13.6 Miscellaneous safety precautions .56
13.7 Safety records . 56
Annex A (Informative) Calculations .57
Annex B (Informative) Selecting a Prover volume for a flowmeter .68
Annex C (Informative) Acceptance criteria and Performance specification .70
Annex D (Informative) Troubleshooting .80
Annex E (Informative) Sphere or detector replacement and twin pairs of detectors. .86
Annex F (Informative) Pulse Interpolation. .88
Annex G (Informative) Alternative designs. .92
Annex H Calibration procedures. .94
Annex I (Informative) Example of prover calibration certificate .99
Bibliography . 104
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oSIST prEN ISO 7278-2:2022
ISO/DIS 7278-2:2021(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/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 28, Petroleum and related products, fuels
and lubricants from natural or synthetic sources, Subcommittee SC 2, Measurement of petroleum and
related products.
This new edition cancels and replaces the first edition (ISO 7278 -2 1988), which has been technically
revised. It also cancels and replaces the first edition of ISO 7278-4, the content of which has been
incorporated. The main changes compared to the previous edition are as follows:
— The content and scope now covers the design of pipe provers given in ISO 7278-2 1988 and the
guidance for operators given in ISO 7278-4.
— The inclusion of small volume provers as described in FDIS ISO 7278-5 which was not published or
now available
— The document now provides guidance on best practice for the design and use of pipe, or displacement,
provers, the incorporation of small volume provers, and taking into account alternative standards
produced by the American Petroleum Institute (API) and the Energy Institute (EI).
— This edition has been produced in conjunction with the Energy Institute and will be published as a
parallel Energy Institute document.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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oSIST prEN ISO 7278-2:2022
ISO/DIS 7278-2:2021(E)
Introduction
In the petroleum industry the term ‘proving’ is used to refer to the calibration of devices used in the
measurement of quantities of crude oil and petroleum products. Proving will use defined methods to
show, or prove, that the result falls within specified acceptance criteria. Proving provides an assurance
that the resultant measurement will provide an acceptable uncertainty for the duty.
A pipe prover, otherwise called a displacement prover, is a volumetric reference device providing
a calibration reference standard for flowmeters with an electronic pulsed output. The fluid remains
contained within the piping system and proving can be carried out dynamically at various flowrates
and pressures without interruption to the flow.
Pipe provers are used extensively within petroleum industry to provide in situ calibration of flowmeters
used for fiscal, custody transfer and pipeline integrity applications. They are used with both crude and
refined oils but may be used with many other fluids within and outside the petroleum industry.
A pipe prover consists of a length of pipe, a section of which has had its internal volume determined
by calibration. A displacer, usually a piston or a tightly fitting sphere or ball, travels along this section
of pipe displacing an accurately determined volume of liquid. This volume can be compared with an
equivalent volume measured by the flowmeter under test.
The calibrated volume of the prover is defined by detection of the displacer passing along the calibrated
section of pipe. Detectors sense the passage of the displacer indicating the start and end of travel
through the calibrated section and they trigger the counting of pulses, hence indicted volume measured,
from the flowmeter.
Pipe provers are of different designs and are manufactured with a wide range of pipe diameters and
volumes. They are available for use as a part of a fiscal measurement system in fixed locations and as
mobile reference devices
Any type of flow meter giving a pulsed output may be calibrated however the volume, design and type
of the prover may impose limitations on the type and size of meter which would be compatible.
This guide describes the design, construction, calibration and use of pipe provers primarily used for
the calibration, proving and verification of flowmeters used for liquid petroleum products and may be
applied to other liquid applications requiring a high standard of measurement accuracy.
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oSIST prEN ISO 7278-2:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 7278-2:2021(E)
Petroleum measurement systems —
Part 2:
Pipe prover design, calibration and operation
WARNING — The use of this document may involve hazardous materials, operations and
equipment. This document does not purport to address all of the safety problems associated
with its use. It is the responsibility of the user of this document to establish appropriate safety
and health practices.
1 Scope
The guidance document provides descriptions of the different types of pipe provers, otherwise known
as displacement provers, currently in use. These include sphere (ball) provers and piston provers
operating in unidirectional and bidirectional forms. It applies to provers operated in conventional,
reduced volume, and small volume modes.
The guidance document describes;
— the calibration methods, installation and use of pipe provers of each type.
— the interaction between a pipe prover and different types of flowmeters is described.
— the calculations used to derive the volumes of liquid (Annex A).
— the expected acceptance criteria for fiscal and custody transfer applications are given as guidance
for both the calibration of pipe provers and when proving flowmeters (Annex C).
The document covers the use of pipe provers for crude oils and light hydrocarbon products which are
liquid at ambient conditions. The principles will apply across applications for a wider range of liquids,
including water. This includes low vapour pressure, chilled and cryogenic products however use with
these products may require additional guidance.
2 Normative references
There are no normative references.
3 Terms, definitions, symbols and units
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
ISO Online brows
...