1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 8310:2012Refrigerated hydrocarbon andnon-petroleum based liquefiedgaseous fuels Generalrequirements for automatictank thermometers on boardmarine carriers and floatingstor
2、ageBS ISO 8310:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 8310:2012. Itsupersedes BS 7575:1992 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PTI/12, Petroleum Measurement and Sampling.A list of organiza
3、tions represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012 ISBN
4、 978 0 580 75083 0 ICS 75.180.30 Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 November 2012. Amendments issued since publicationDate T e x t a f f e c t e dB
5、S ISO 8310:2012 ISO 2012Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels General requirements for automatic tank thermometers on board marine carriers and floating storageHydrocarbures rfrigrs et combustibles gazeux liqufis base non ptrolire Exigences gnrales pour les thermom
6、tres de rservoir automatiques bord des transporteurs de cargaison en mer et des stocks flottantsINTERNATIONAL STANDARDISO8310Second edition2012-11-01Reference numberISO 8310:2012(E)BS ISO 8310:2012ISO 8310:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved
7、. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.
8、ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 8310:2012ISO 8310:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Te
9、rms and definitions . 14 Safety precautions 24.1 General . 24.2 Equipment precautions . 35 Design requirements 35.1 General . 35.2 Temperature sensors . 35.3 Indicating device . 45.4 Installation 45.5 Provisions for routine maintenance and verification 45.6 Provision against sudden malfunctions 45.7
10、 Dynamic response 45.8 Measurable range . 45.9 Data processing and reporting 45.10 Compensation for variation of cargo temperatures 55.11 Sealing, security and unsealing . 55.12 Redundancy . 55.13 Data communication 56 Calibration and accuracy verification 56.1 General . 56.2 Calibration reference .
11、 66.3 Calibration and accuracy verification at factory 66.4 Calibration and accuracy verification after installation 66.5 Periodic accuracy verification 97 Accuracy requirement 97.1 Overall error 97.2 Resolution 108 ATT calibration records .10Annex A (informative) Information on platinum resistance
12、thermometers .11Bibliography .12BS ISO 8310:2012ISO 8310:2012(E)ForewordISO (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 com
13、mittees. 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
14、 International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft Internationa
15、l Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the
16、subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 8310 was prepared by Technical Committee ISO/TC 28, Petroleum products and lubricants, Subcommittee SC 5, Measurement of refrigerated hydrocarbon and non-petroleum based liquefied gaseous fu
17、els.This second edition cancels and replaces the first edition (ISO 8310:1991), which has been technically revised.iv ISO 2012 All rights reservedBS ISO 8310:2012ISO 8310:2012(E)IntroductionLarge quantities of liquefied natural gas (LNG), liquefied petroleum gas (LPG) and other liquefied gases are u
18、sually transported by marine carriers dedicated for these applications and traded based on static measurement on board by automatic tank measurement. Such an automatic tank measurement may be a part of the custody transfer measurement system (CTMS) which involves determination of liquid/vapour inter
19、face, i.e. liquid level, average temperatures of liquid and vapour, and vapour pressure. The volumetric quantity of the liquid and gas is then computed with the tank capacity table based on which the delivered quantity in terms of energy content or mass is calculated.In most cases, shore tank measur
20、ement is not used due to the active and dynamic conditions of the shore tank operations. In the absence of other means of acceptable measurement, custody transfer measurement usually takes place on board the carrier or floating production storage offshore (FPSO) and floating storage offshore (FSO).
21、Liquid cargo density is very sensitive to temperature; therefore, obtaining accurate temperature readings is extremely important. For example, a change of 0,2 C for liquid methane cargo results in a change in density of approximately 0,07 %.This International Standard also discusses use of automatic
22、 tank thermometers on board marine vessels for other volatile, non-petroleum liquids in fully refrigerated conditions. Many of these non-petroleum liquids, such as di-methyl ether (DME) are measured in a similar manner to that used for fully refrigerated LPGs.Values of temperature in this Internatio
23、nal Standard are in terms of the International Temperature Scale of 1990, ITS-90. Temperatures in degrees Celsius are denoted by the symbol t. ISO 2012 All rights reserved vBS ISO 8310:2012BS ISO 8310:2012Refrigerated hydrocarbon and non-petroleum based liquefied gaseous fuels General requirements f
24、or automatic tank thermometers on board marine carriers and floating storage1 ScopeThis International Standard specifies the essential requirements and verification procedures for automatic tank thermometers (ATTs) consisting of platinum resistance thermometers (PRT) and an indicating device used fo
25、r custody transfer measurement of liquefied natural gas, liquefied petroleum and chemical gases on board ships. Temperature detectors other than PRT are considered acceptable for use in the custody transfer service of liquefied gases if they meet the performance requirements of this International St
26、andard and are approved by national regulations.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition
27、of the referenced document (including any amendments) applies.IEC 60751, Industrial platinum resistance thermometers and platinum temperature sensors3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1automatic tank gaugeATGautomatic level gaugeALGi
28、nstrument that automatically measures and displays liquid levels or ullages in one or more tanks, either continuously, periodically or on demand3.2automatic tank gauging systemATG systemsystem that includes ATGs at the cargo tanks and control/display unit that processes and displays output signals f
29、rom the ATG along with any other parameters required to determine the liquid level, i.e. liquid/vapour interface3.3automatic tank thermometerATTautomatic tank temperature systeminstrument that continuously measures temperature in cargo tanksNOTE 1 An ATT typically includes temperature sensors, such
30、as PRTs, field-mounted transmitters for electronic signal transmission, and indicating device(s).NOTE 2 ATTs on liquefied gas carriers are usually multiple-point ATTs which consist of three or more temperature sensors, such as PRTs, to measure the temperatures at selected heights in the cargo tank.I
31、NTERNATIONAL STANDARD ISO 8310:2012(E) ISO 2012 All rights reserved 1BS ISO 8310:2012ISO 8310:2012(E)3.4custody transfer measurement systemCTMSsystem that processes inputs from an ATG system, an ATT, pressure gauges, etc. and provides custody transfer measurement information on board, generating doc
32、uments with regard to custody transfer of liquefied gasesNOTE An ATT can be incorporated as part of a CTMS.3.5gas dangerous space or zonespace or zone defined by the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code)3.6indicating devicedisplayi
33、ng deviceset of components of a measuring instrument intended to indicate the measured value3.7inherent errorintrinsic errorerror of a gauge when it is tested against a reference standard under controlled conditions as specified by the manufacturer3.8nominal resistanceexpected resistance R0of a PRT
34、at 0 C, declared by the manufacturer and shown in the thermometer marking, usually rounded to the nearest ohm3.9nominal temperature/resistance relationshiprelationship between temperature and resistance of a nominal PRT3.10platinum resistance thermometerPRTresistance temperature detectorRTDtemperatu
35、re-responsive device consisting of one or more sensing platinum resistors within a protective sheath, internal connecting wires and external terminals to permit connection of electrical measurement instruments3.11uncertaintynon-negative parameter characterizing the dispersion of the quantity values
36、being attributed to a measurand, based on the information used4 Safety precautions4.1 GeneralNothing contained in this International Standard is intended to supersede any regulatory requirements or recommended operating practices issued by organizations such as the International Maritime Organizatio
37、n (IMO), International Chamber of Shipping (ICS), Oil Companies International Marine Forum (OCIMF), International Association of Classification Societies (IACS) and individual operating companies, nor is this International Standard intended to conflict with any safety or environmental considerations
38、, local regulations, or the specific provisions of any contract.2 ISO 2012 All rights reservedBS ISO 8310:2012ISO 8310:2012(E)4.2 Equipment precautions4.2.1 GeneralAll electric components of an ATT for use in electrically classified areas shall meet the electrical area classification. They shall con
39、form to applicable sections of the national and/or international electrical safety standards. All ATTs shall be maintained in a safe operating condition and manufacturers maintenance instructions should be complied with.4.2.2 Mechanical rigidityAll ATTs shall be capable of withstanding the pressure,
40、 temperature, dynamic loads generated from rolling/pitching, and sloshing from environmental conditions likely to be encountered in the service.Where a PRT is installed near a submerged pump or the end of a loading/unloading line in a cargo tank, appropriate measures shall be applied to prevent the
41、ATT from being affected by the vortex or vaporization, i.e. boiling, of cargo caused by cargo loading or cargo unloading operations. In addition, all PRTs shall be mounted such that they are not affected by the spray of liquefied gas whenever the spray nozzles are in operation.4.2.3 Gastight designA
42、ll parts of ATTs exposed to a gas dangerous space or zone shall be of gastight construction.4.2.4 Compatibility with cargoAll parts of the ATT in contact with liquefied gases or their vapour shall be chemically compatible with the product, to avoid both product contamination and corrosion of the ATT
43、.4.2.5 Tolerance against low temperaturesATTs shall be designed to measure the low temperatures encountered in refrigerated liquefied gas service. They shall also be designed to withstand the low-temperature thermal contraction of their components and of the tanks. Additionally, change in the height
44、 of PRT in the tanks by such thermal contraction shall be compensated for in an appropriate manner.4.2.6 Type approvalThe design and installation of ATTs shall be subject to the approval of a national metrology institute (NMI) or class society. For electrical considerations, refer to IACS Unified Re
45、quirements E1010. Type approval is normally issued after an ATT has been subjected to a specific series of tests.5 Design requirements5.1 GeneralThe following design requirements apply to all types of ATTs on liquefied gas carriers, FPSOs and FSOs. These requirements, which may be in addition to the
46、 technical specifications by the ATT manufacturer, should be met where they are applicable.5.2 Temperature sensorsTemperature sensors used for custody transfer measurement of liquefied gases on board ships shall be either three- or four-wire type PRTs as described in IEC 60751. The relationship of t
47、emperature and resistance of the PRTs is described by a temperature/resistance relationship (see Annex A). ISO 2012 All rights reserved 3BS ISO 8310:2012ISO 8310:2012(E)Each PRT shall be subject to the following routine production tests:a) insulation resistance at ambient temperature;b) sheath integ
48、rity test;c) dimensional test;d) tolerance acceptance test.NOTE See IEC 60751 for the details of the routine production test.The manufacturer shall calibrate each PRT and establish its nominal resistance (R0) and constants A, B and C in the temperature/resistance relationship.Identification such as
49、the serial number should be clearly and indelibly marked on each PRT.5.3 Indicating deviceIndicating devices with analogue inputs shall have a high-impedance input circuit so as to minimize error.5.4 InstallationThe number of PRTs in a tank depends on the capacity and the height of the tank; however, IGC Code requires a minimum of three. In the case of large LNG carriers, there may be five or more PRTs in each tank with each PRT supported by a secondary PRT mounted adjacent to the primary PRT (see 5.12).At least one PRT shall be loca
