ISO INTERNATIONAL STANDARD 18453 First edition 2004-07-01 Natural gas - Correlation between water content and water dew point Gaz naturel- Corrélation entre la teneur en eau et le point de rosee de I'eau Reference number ISO 18453:2004(E) @ ISO 2004 ISO 18453:2004(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademarkof Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation ISO 2004 All rights reserved. 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 IsO's memberbody in the country of the requester. ISO copyright office Case postale 56CH-1211 Geneva 20 Tel. + 4122 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ISo2004-Allrightsreserved ISO 18453:2004(E) Contents Page Foreword Introduction 1 Scope. 2 Terms and definitions 3 Development of the correlation .. 4 Range of application and uncertainty of the correlation 5 Correlation... AnnexA(normative)Thermodynamicprinciples Annex B (informative) Traceability Annex C (informative) Examples of calculations...... Annex D (informative) Subscripts, symbols, units, conversion factors and abbreviations. Bibliography .. @Iso 2004-All rights reserved ili ISO 18453:2004(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies non-governmental,inliaisonwithIsO,alsotakepartinthe work.Isocollaboratescloselywiththe International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2. 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 subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 18453 was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee SC 1, Analysis of naturalgas. iv IsO2004-Allrightsreserveo ISO18453:2004(E) Introduction IsO/Tc 193, Natural gas, was established in May 1989, with the task of creating new standards, and updating existing standards relevant to natural gas. This includes gas analysis, direct measurement of properties quality designation and traceability. This document provides a reliable mathematical relationship between water content and water dew point in principles is given in Annex A; information relating to the traceability, applications and uncertainties associated with this work is given in Annex B. Some of the operational problems in the natural gas industry can be traced back to water content in natural gases. Even with low water vapour content in the gas, changing operating pressure and temperature avoid these problems, expensive dehydration units have been installed by natural gas companies. The design and cost of these installations depend on the exact knowledge of the water content at the dew point and the (contractually) required water content. decadesfocus onthedetermination of water content ratherthanon waterdew point.Therefore,if thewatel contentismeasured,acorrelationisneededfortheexpressionofwaterdewpoint. The GERG1) Group identified a need to build a comprehensive and accurate database of measured water content and corresponding water dew point values for a number of representative natural gases in the range o