1、BRITISH STANDARD BSENISO 7278-2:1996 Incorporating Amendment No. 1 BS6866-2:1990 renumbered Liquid hydrocarbons Dynamic measurement Proving systems for volumetric meters Part 2: Pipe provers The European Standard ENISO7278-2:1995 has the status of a BritishStandardBSENISO7278-2:1996 This BritishStan
2、dard, having been prepared under the directionof the Petroleum Standards Policy Committee, waspublished under the authorityof the Board of BSI andcomes into effect on 31August1990 BSI01-2000 The following BSI references relate to the work on this standard: Committee reference PTC/12 Draft for commen
3、t85/55226DC ISBN 0 580 18713 6 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Petroleum Standards Policy Committee (PTC/-) to Technical Committee PTC/12, upon which the following bodies were represented: Department of Energy (Gas and Oil
4、Measurement Branch) Department of Trade and Industry (National Engineering Laboratory) Department of Transport (Marine Directorate) General Council of British Shipping Institute of Petroleum Royal Institution of Naval Architects Salvage Association The following bodies were also represented in the d
5、rafting of the standard, through subcommittees and panels: GAMBICA (BEAMA Ltd.) Institute of Measurement and Control United Kingdom Offshore Operators Association Amendments issued since publication Amd. No. Date Comments 8899 June1996 Indicated by a sideline in the marginBSENISO7278-2:1996 BSI 01-2
6、000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 References 3 3 Definitions 3 4 Description of systems 4 5 Essential performance requirements 5 6 Equipment 5 7 Design of pipe provers 8 8 Installation 1
7、0 9 Calibration 11 Annex A The use of pipe provers with four detectors 19 Annex B Example of the calculation of the design parameters of a pipe prover 22 Figure 1 Typical unidirectional return-type prover system 16 Figure 2 Typical bidirectional straight-type piston prover system 17 Figure 3 Typical
8、 bidirectional U-type sphere prover system 18 Figure 4 Simultaneous use of two counters with a four-detector prover 21 Figure 5 Temporary connection of counters to measure n 1and n 2 21 Publications referred to Inside back coverBSENISO7278-2:1996 ii BSI 01-2000 National foreword This Part of BS EN I
9、SO7278 has been prepared by Technical Committee PTI/12 (formerly PTC/12) and is the English language version of EN ISO7278-2:1996 Liquid hydrocarbonsDynamic measurementProving systems for volumetric meters Part2: Pipe provers published by the European Committee for Standardization (CEN). It is ident
10、ical with ISO7278-2:1988 published by the International Organization for Standardization (ISO). ISO5024:1976 is related to BS5579:1978 “Specification for standard reference conditions for measurement of petroleum liquids and gases”; the standard reference conditions referred to in1.3 are identical t
11、o those given in BS5579. 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. Cross-references
12、 International Standard Corresponding BritishStandard ISO91-1:1982 BS6441:1983 Schedule for petroleum measurement tables (Identical) ISO2715:1981 BS6619 Methods for volumetric measurement of liquid hydrocarbons Part2:1984 Turbine meter-systems (Identical) ISO4267-2:1988 BS7286 Method for calculation
13、 of petroleum and liquid petroleum products Part2:1990 Dynamic measurement (Identical) ISO7278-3:1986 BS6866 Proving systems for meters used in dynamic measurement of liquid hydrocarbons Part3:1987 Methods for pulse interpolation (Identical) ISO8222:1987 BS6922:1988 Specification for temperature cor
14、rections for use in the calibration of reference measuring systems for petroleum measurement (Identical) Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, pages2 to22, an inside back cover and a back cover. This standard has been updat
15、ed (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO7278-2 October1995 ICS75.200 Descriptors: Petroleum products, hydrocarbons, liquid flow, flowmeters, tests
16、, dynamic tests, flow measurement English version Liquid hydrocarbonsDynamic measurement Provingsystems for volumetric meters Part2:Pipeprovers (ISO7278-2:1988) Hydrocarbures liquidesMesurage dynamique Systmes dtalonnage des compteurs volumtriquesPartie2: Tubes talons (ISO7278-2:1988) Flssige Kohlen
17、wasserstoffeDynamische MessungPrfsysteme fr volumetrische MegerteTeil2: Rohrprfer (ISO7278-2:1988) This European Standard was approved by CEN on1995-09-09. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the s
18、tatus 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 any CEN member. This European Standard exists in three official versions (English, French, German).
19、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. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, German
20、y, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland andUnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All right
21、s of reproduction and communication in any form and by any means reserved in all countries to CEN and its members. Ref.No.ENISO7278-2:1995EENISO7278-2:1995 BSI 01-2000 2 Foreword The text of the International Standard from ISO/TC28, Petroleum products and lubricants, of the International Organizatio
22、n for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC19, Petroleum products, lubricants and related products. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at t
23、he 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 implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Irelan
24、d, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the UnitedKingdom.ENISO7278-2:1995 BSI 01-2000 3 0 Introduction Pipe provers are used as volume standards for the calibration of liquid meters. The purpose of this part of ISO7278 is to outline the essential elements
25、 of a pipe prover, to provide specifications for its performance, and to give guidance on its design, installation and calibration. Pipe provers discussedin this part of ISO7278 are of the running-start/running-stop type, in which flow is uninterrupted during proving, thus permitting the meter to be
26、 proved under its normal operating conditions. This type of prover includes a calibrated section of pipe in which a displacer travels, actuating detection devices which produce electrical signals as the displacer passes each end of the calibrated portion. The displacer finally stops at the end of th
27、e run as it enters a region where the flow bypasses it. Both stationary and mobile provers may be constructed on this principle. The calibrated section of the prover may be straight or folded (U-shaped), and the design may be such that the displacer moves around a closed loop in only one direction (
28、unidirectional) or, alternatively, in both directions (bidirectional). ISO7278 consists of the following parts, under the general title Liquid hydrocarbonsDynamic measurementProving systems for volumetric meters: Part 1: General principles; Part 2: Pipe provers; Part 3: Pulse interpolation technique
29、s. Annex A forms an integral part of this part of ISO7278. Annex B is for information only. 1 Scope and field of application 1.1 This part of ISO7278 provides guidance for the design, installation and calibration of pipe provers. Calculation techniques for use when calibrating and operating provers
30、are detailed in ISO4267-2. 1.2 Most of the material in this part of ISO7278 is general in that it applies to pipe provers for use with different liquids and types of meters and for proving them in different services. This part of ISO7278 does not apply to the newer “small volume” or “compact” prover
31、s. 1.3 The standard reference conditions for petroleum measurement are a temperature of15 C and a pressure of101325Pa as specified in ISO5024. NOTEIn some countries other reference temperatures are used, e.g.20 C and60 F. 2 References ISO2715, Liquid hydrocarbonsVolumetric measurement by turbine met
32、er systems. ISO4267-2, Petroleum and liquid petroleum productsCalculation of oil quantities Part2:Dynamic measurement 1) . ISO5024, Petroleum liquids and gases MeasurementStandard reference conditions. ISO7278-3, Liquid hydrocarbonsDynamic measurementProving systems for volumetric metersPart3: Pulse
33、 interpolation techniques. ISO8222, Petroleum measurement systems CalibrationTemperature corrections for use with volumetric reference measuring systems. 3 Definitions For the purposes of this part of ISO7278, the following definitions apply: 3.1 base volume the volume of a prover calibrated section
34、, i.e.the length between the detectors, at specified reference conditions of temperature and pressure 3.2 K-factor the ratio of the number of electrical pulses emitted by a meter during a proving run to the volume of liquid passed through the meter 3.3 meter factor the ratio of the actual volume of
35、a liquid passed through a meter to the volume indicated by the meter 3.4 prover calibration the procedure for determining the base volume ofaprover 3.5 proving; proof the determination of the meter factor or K-factor 3.6 range the difference between the highest and the lowest values within a batch o
36、f results 1) At present at the stage of draft.ENISO7278-2:1995 4 BSI 01-2000 4 Description of systems 4.1 General 4.1.1 There are several types of pipe prover, all of which are relatively simple and commercially available. All types operate on a common principle, namely the precisely measured displa
37、cement of a volume of liquid in a calibrated section of pipe between two signalling detectors, by means of a displacer (a slightly oversized sphere or piston) being driven along the pipe by the liquid stream being metered. While the displacer is travelling between the two detectors, the output of th
38、e meter is recorded automatically. Pipe provers may be operated automatically or manually. 4.1.2 A meter being proved on a continuous-flow basis shall, at the time of proof, be connected to a counter which can be started or stopped instantly by the signalling detectors. The counter is usually of the
39、 electronic-pulse-counting type. The counter is started and stopped by the displacing device actuating the detector at each extremity of the calibrated section. 4.1.3 There are two main types of pipe prover: unidirectional and bidirectional. The unidirectional prover allows the displacer to travel i
40、n only one direction through the proving section, and has a transfer arrangement for returning the displacer to its starting position. The bidirectional type allows the displacer to move first in one direction, then in the other. It therefore incorporates a means of reversing the flow through the pi
41、pe prover. (SeeFigure 1, Figure 2 and Figure 3.) 4.1.4 Both unidirectional and bidirectional provers shall be constructed so that the full flow through the meter being proved passes through the prover. 4.2 Unidirectional provers 4.2.1 Unidirectional provers may be subdivided into two categories depe
42、nding on the manner in which the displacer is handled, namely the manual-return in-line type sometimes referred to as a “measured distance” type, and the automatic-return or circulating type, often called the “endless loop” type. a) The manual-return unidirectional prover is an elementary form of in
43、-line prover which uses a section of pipeline as the prover section. The entire metered stream may flow continuously through the prover even when the prover is not being used for proving. Detectors are placed at selected points which define the calibrated volume of the prover section. A displacer la
44、unching device is upstream of the prover section, and receiving facilities are installed at some point downstream of the prover section. Usually, conventional launching and receiving scraper traps are used for this purpose. To make a proving run, a displacer (a sphere or specially designed piston) i
45、s launched, allowed to traverse the calibrated section, received downstream and then manually transported back to the launching site. b) The automatic-return unidirectional (endless loop) prover has evolved from the prover described in4.2.1 a) and is shown in Figure 1. In this endless loop, the pipi
46、ng is arranged so that the downstream end of the looped section crosses over and above the upstream end of the loop. The interchange is the means whereby the displacer is transferred from the downstream end to the upstream end of the loop without removing it from the prover. The displacer detectors
47、are located at a suitable distance from the interchange inside the looped portion. Such endless prover loops may be manually operated or they may be automated so that the entire sequence for proving a meter can be actuated by a single action. The metered stream may be permitted to run through the pr
48、over when the prover is not being used for proving, and the prover need not be isolated from the carrier line unless desired. This permits the movement of several different types of liquid in succession through the prover, and affords a self-flushing action which minimizes intermixing between them,
49、as well as providing temperature stabilization. 4.2.2 A meter proof run in a unidirectional prover consists of a single one-way run, therefore the base volume of a unidirectional prover is the volume of liquid, corrected to standard temperature and pressure conditions, displaced between the detectors during a single trip of the displacer.ENISO7278-2:1995 BSI 01-2000 5 4.3 Bidirectional provers The bidirectional prover has a length of pipe in which the displacer travels back and forth, actuating a detector at each
