1、BRITISH STANDARD BS EN ISO 6551:1996 Incorporating Amendment No. 1 BS6439:1983 renumbered Petroleum liquids and gases Fidelity and security of dynamic measurement Cabled transmission of electric and/or electronic pulsed data The European Standard EN ISO6551:1995 has the status of a British Standard
2、ICS 75.200BSEN ISO 6551:1996 This British Standard, having been prepared under the directionof the Petroleum Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 30December1983 BSI 10-1999 The following BSI references relate to the work on this standard:
3、Committee reference PTC/12 Draft for comment 81/52261 DC ISBN 0 580 135640 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Petroleum Standards Committee (PTC/-) to Technical Committee PTC/12 upon which the following bodies were represent
4、ed: Association of Commodity Cargo Superintendents and Surveyors British Gas corporation Department of Energy (Gas Standards) Department of Trade and Industry (Marine Division) Department of Trade and Industry (National Engineering Laboratory) Department of Trade and Industry (National Weights and M
5、easures Laboratory) General Council of British Shipping Institute of Petroleum Institution of Gas Engineers The Salvage Association UK Offshore Operators Association Ltd. United Kingdom Petroleum Industry Advisory Committee Amendments issued since publication Amd. No. Date of issue Comments 8894 Mar
6、ch 1996 Indicated by a sideline in the marginBSEN ISO 6551:1996 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 Definitions 4 3 Levels of security 4 4 System design principles and quality 9 5
7、Precautions 10 6 Installation 10 7 Commissioning and testing 11 8 Inspection and maintenance 12 Figure 1 Typical functional arrangement for pulse security system; Level E 5 Figure 2 Typical functional arrangement for pulse security system; Level D 6 Figure 3 Typical functional arrangement for pulse
8、security system; Level C 7 Figure 4 Typical functional arrangement for pulse security system; Level B 8 Figure 5 Typical functional arrangement for pulse security system; Level A 9BSEN ISO 6551:1996 ii BSI 10-1999 National foreword This British Standard was prepared by PTC/12 and is the English lang
9、uage version of EN ISO6551:1995 Petroleum liquids and gases Fidelity and security of dynamic measurement Cabled transmission of electric and/or electronic pulsed data published by the European Committee for Standardization (CEN). It is identical with ISO6551:1982 published by the International Organ
10、ization for Standardization (ISO). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summar
11、y of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, pages 2 to 14 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside fro
12、nt cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 6551 October 1995 ICS 75.200 Descriptors: Petroleum products, liquids, gases, petroleum products transportation, pulsating flow, quantities, measurement, accuracy, definitions, safety requirements, designation, inspection English vers
13、ion Petroleum liquids and gases Fidelity and security of dynamic measurement Cabled transmission of electric and/or electronic pulsed data (ISO 6551:1982) Liquides et gaz de ptrole Fidlit et scurit des mesures dynamiques Systmes de transmission par cbles de donnes, sous forme dimplusions lectriques
14、et/ou lectroniques (ISO 6551:1982) Minerallflssigkeiten und-gase Genauigkeit und Sicherheit der dynamischen Messung Elektrische und/oder elektronische Impuls-Datenbertragung ber Kabel (ISO6551:1982) This European Standard was approved by CEN on1995-09-09. CEN members are bound to comply with the CEN
15、/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 Central Secretariat or to
16、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 Central Secretariat has the same status as the official versions.
17、 CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation
18、Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members. Ref. No. EN ISO 6551:1995 EEN ISO 6551:1995 BSI 10-1999 2 Foreword The text of the
19、International Standard from ISO/TC 28, Petroleum products and lubricants, of the International Organization for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC 19, Petroleum products, lubricants and related products. This European Standard shall be
20、given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April1996, and conflicting national standards shall be withdrawn at the latest by April1996. According to CEN/CENELEC Internal Regulations, the following countries are bound to imp
21、lement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.EN ISO 6551:1995 BSI 10-1999 3 0 Introduction 0.1 Quantitative measurements are required a
22、t many stages in production, transportation, refining and marketing of petroleum and its products. They form the basis of royalty, fiscal and custody transfer accounting and provide the means of stock and loss control. The use of agreed standardized measurement equipment and procedures obviates disp
23、utes over quantities, enabling these to be determined with an accuracy mutually acceptable to all parties to a transaction and at the most economical cost for the method of measurement selected. 0.2 During the last decade there has been a rapid increase in the use of electrical or electronic data-tr
24、ansmission systems designed to facilitate the determination of physical quantities such as length, mass, volume, etc. Such systems can be vulnerable to disturbances arising from the environment in which they are used, and also from functional failures, all or any of which may affect the integrity of
25、 the resulting measurement. The purpose of this International Standard is to assist manufacturers and users of electrical or electronic pulsed data-transmission systems used in the metering of fluids to meet certain criteria for the design, installation, use and maintenance of such equipment. The ob
26、ject is to establish and maintain the credibility of indicated data against influences acting to impair the fidelity of the system. 0.3 This International Standard recommends solutions for fidelity and security problems which constitute good practice in this field at this time, but it is not claimed
27、 that the recommendations are wholly comprehensive. The recommendations are, however, considered to be practicable, and to satisfy the immediate needs of industries associated with meter proving and the metering of hydrocarbons and hydrocarbon products in the bulk commercial, royalty metering, reven
28、ue accounting and custody transfer fields in general. 0.4 It is not intended that these recommendations should act to inhibit technological progress in the industry, and therefore amendments may be introduced as and when required. The principles may be applied to the metering of solids. 0.5 Clauses
29、have been included on safety and other precautions that constitute good practice. Although every care is taken to include such clauses wherever necessary, it is impossible to cover all contingencies. In the designing of measurement and sampling operations, attention should also be given to general c
30、odes of safe practice for petroleum operations. The operator or other user of this measurement standard should work according to accepted safe practices and comply with all relevant regulatory requirements. 0.6 This International Standard is recommended for general adoption but it must therefore be
31、read and interpreted in conjunction with legal metrology (weights and measures), safety and other regulations in force in a particular country in which it is intended to apply it. 1) 1 Scope and field of application 1.1 General This International Standard establishes guidelines for ensuring the fide
32、lity and security of pulsed data cabled transmission systems utilized for the metering of fluids (see the note), a main objective being to ensure the integrity of the primary indication (see2.2.5). NOTECompliance with the requirements of this International Standard does not increase the basic precis
33、ion of measurement, either in the electrical or electronic section of the system, or in the overall system which includes the meter(s). 1.2 Levels of security 1.2.1 In order to achieve different levels of security (see the note and clause3) which can be applied to such systems, criteria and recommen
34、dations for the design, installation, use and maintenance of the relevant equipment are laid down. NOTEThe levels of security are designated E to A, from the lowest to the highest order of security respectively. For the majority of applications, the lower levels are considered to be adequate and at
35、the time of the publication of this International Standard, there is no known system for which Level A security is considered to be a necessity. 1.2.2 This International Standard does not define which levels of security are to be used for a particular system application. 1.3 Safety and regulatory re
36、quirements 1.3.1 Regulatory requirements, including those for safety, are not specifically covered in detail but certain general cautionary notes on safety are included for guidance (see the note). 1) In the case of marine applications, the safety requirements of the appropriate Ship Classification
37、Society will apply. This includes offshore production facilities for which a Society has been appointed as the Certifying Authority for the compliance of the installation with official safety standards.EN ISO 6551:1995 4 BSI 10-1999 NOTECompliance with this International Standard in no way absolves
38、manufacturers and users of systems and equipment from meeting all relevant legal metrology (weights and measures), safety and other regulations applicable in the country in which it is intended to use a system. Special attention is drawn to0.5 and0.6 of the Introduction. 2 Definitions 2.1 In prepari
39、ng this glossary, the following two principles have been followed: a) To select for definition the minimum of basic terms used in the text and to apply to them an unequivocal meaning. It is recommended that these standardized terms, as defined, should be used in the context of the application of thi
40、s International Standard. b) To exclude other terms used in the text which are adequately defined elsewhere, or the meanings of which are self-evident. 2.2 For the purpose of this International Standard, the following definitions shall apply. 2.2.1 fidelity the exactitude with which the primary indi
41、cation reproduces the inherent precision of the measurement 2.2.2 flow (rate or quantity) transducer a device for converting the indication of flow (rate or quantity) to a usable output 2.2.3 totalizer a device which sums the indications of an indicating device; it may or may not be resettable to ze
42、ro (see4.4) 2.2.4 noise unwanted signals which may impair fidelity, and which occur for periods exceeding0,2 s 2.2.5 primary indication the combination of the transducer(s) output(s), the transmission cabling, the signal conditioning, processing and scaling, and the indicator with or without totaliz
43、er and their readings, the whole of which produces the final reference for the transaction 2.2.6 secondary indication (auxiliary or ancillary indication) any equipment which separately or in combination provides indication of the quantity measured, but which does not form part of the primary indicat
44、ion 2.2.7 security the state or means of ensuring fidelity. The degree or level of security given by a minimum basic arrangement, can be increased by additional equipment 2.2.8 transients disturbances having a duration of0,2s or less 2.2.9 pulse transmitter a device for converting the output from a
45、transducer into a pulsed signal of low source impedance over the full operating frequency range (with pre-amplification if necessary) 2.2.10 unrevealed error any lack of fidelity outside the prescribed limits of error, including errors caused by functional failure and by external influences 3 Levels
46、 of security 3.1 Designation of security levels In this International Standard, five levels of security are identified and designated, of which Level E represents the minimum acceptable level. Typical examples of these five levels are shown diagrammatically inFigure 1 toFigure 5, and are described b
47、elow. 3.1.1 Level E Error reduction is achieved solely by correctly installed apparatus of good quality. This is a straightforward scaler totalizer system. 3.1.2 Level D Manual error monitoring at specified intervals by methods of comparison. This level of security is intended to give protection aga
48、inst functional errors and failures and is a method of verification by manual action. It has the means for checking the read-out visually against an independent totalizing system. 3.1.3 Level C Automatic error monitoring and error indication at specified intervals by methods of comparison.EN ISO 655
49、1:1995 BSI 10-1999 5 This level of security is intended to give protection against functional errors and failures and this may be achieved by design methods acceptable to an approving authority (if appropriate). The time intervals for error monitoring are subject to revision in the light of experience gained. 3.1.4 Level B Continuous monitoring, error indication and alarm signalling by methods of comparison. This level of security is intended to give warning of transients and other spurious influences, supply borne and radiated
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