SIST EN ISO 11541:2003

SLOVENSKI STANDARD
SIST EN ISO 11541:2003
01-februar-2003
=HPHOMVNLSOLQ'RORþHYDQMHYRGHSULYLVRNHPWODNX,62
Natural gas - Determination of water content at high pressure (ISO 11541:1997)
Erdgas - Bestimmung des Wassergehaltes unter hohem Druck (ISO 11541:1997)
Gaz naturel - Dosage de l'eau a haute pression (ISO 11541:1997)
Ta slovenski standard je istoveten z: EN ISO 11541:2002
ICS:
75.060 Zemeljski plin Natural gas
SIST EN ISO 11541:2003 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11541:2003

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SIST EN ISO 11541:2003
EUROPEAN STANDARD
EN ISO 11541
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2002
ICS 75.060
English version
Natural gas - Determination of water content at high pressure
(ISO 11541:1997)
Gaz naturel - Dosage de l'eau à haute pression (ISO Erdgas - Bestimmung des Wassergehaltes unter hohem
11541:1997) Druck (ISO 11541:1997)
This European Standard was approved by CEN on 9 October 2002.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11541:2002 E
worldwide for CEN national Members.

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SIST EN ISO 11541:2003
EN ISO 11541:2002 (E)
Foreword
The text of ISO 11541:1997 has been prepared by Technical Committee ISO/TC 193 "Natural
gas" of the International Organization for Standardization (ISO) and has been taken over as EN
ISO 11541:2002 by CMC.
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 2003, and conflicting national standards
shall be withdrawn at the latest by May 2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 11541:1997 has been approved by CEN as EN ISO 11541:2002 without any
modifications.
NOTE  Normative references to International Standards are listed in Annex ZA (normative).
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SIST EN ISO 11541:2003
EN ISO 11541:2002 (E)
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated
by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 10715 1997 Natural gas - Sampling guidelines EN ISO 10715 2000
3

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SIST EN ISO 11541:2003

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SIST EN ISO 11541:2003
IS0
INTERNATIONAL
11541
STANDARD
First edition
1997-02-I 5
Natural gas - Determination of water
content at high pressure
Gaz nature/ - Dosage de I’eau 9 haute presslon
Reference number
IS0 11541:1997(E)

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SIST EN ISO 11541:2003
IS0 11541:1997(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be rep-
resented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
Draft International 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.
International Standard IS0 11541 was prepared by Technical Committee
lSO/TC 193, Natural gas, Subcommittee SC 1, Analysis of natural gas.
0 IS0 1997
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 the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Internet centraI@iso.ch
x.400 c=ch; a=400net; p=iso; o=isocs; s=central
Printed in Switzerland
ii

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SIST EN ISO 11541:2003
IS0 11541:1997(E)
INTERNATIONAL STANDARD o ~so
Natural gas - Determination of water content at high
pressure
1 Scope
Water vapour may be present in natural gas due to, for example, natural occurrence in the well production stream,
the storage of gas in underground reservoirs, transmission or distribution through mains containing moisture or
other reasons.
This International Standard specifies a method of determining the water content of natural gas under pressures of
more than 1 MPa, the upper pressure limit being determined by the maximum pressure that the apparatus can
withstand. It is applicable to sweet natural gas and sour natural gas, containing hydrogen sulfide, with a water
concentration of 10 mg/m3 or more?)
NOTE - Test data may be affected by alcohols, mercaptans, hydrogen sulfide and glycol contained in the sample gas, as
these compounds react with the phosphorus pentoxide (P205) used to absorb the water vapour in the gas.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this
International Standard. At the time of publication, the edition indicated was valid. All standards are subject to
revision, and parties to agreements based on this International Standard are encouraged to investigate the
possibility of applying the most recent edition of the standard indicated below. Members of IEC and IS0 maintain
registers of currently valid International Standards.
IS0 10715: --*I, Natural gas - Sampling guidelines.
3 Principle
A measured volume of gas is passed through an absorption tube filled with phosphorus pentoxide. Water
contained in the gas is absorbed by the phosphorus pentoxide and phosphoric acid is formed. The increase in the
mass of the tube is deemed to be the mass of water present in the gas. The absorption of water vapour at pipeline
pressure is favoured over absorption at ambient pressure for the following reasons:
the water vapour partial pressure is high;
a)
b) the necessary amount of gas is transmitted in a shorter time.
1 In this International Standard, all volumes are expressed at 288,15 K and 101,325 kPa.
2) To be published.
1

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SIST EN ISO 11541:2003
0 IS0
IS0 11541:1997(E)
4 Reagents and materials
41 . Granulated phosphorus pentoxide, on a solid support with a moisture indicator (commercially available).
WARNING - Observe all safety precautions for phosphorus pentoxide. Any contact with skin or eyes and
inhalation of vapours shall be avoided. Appropriate protective clothing shall be worn while working with
phosphorous pentoxide.
4.2 Silica wool.
WARNING - If not handled properly, silica wool can cause silicosis. A respirator is recommended for safe
handling.
5 Apparatus
51 . The test apparatus consists of the following components (see figures 1, 2 and 3):
5.1 .I Pressure vessel body.
5.1.2 End piece for pressure vessel.
5.1.3 Filter tube, made of glass, with an outside diameter of 20 mm and a length of 32 mm, filled with silica
wool.
5.1.4 Coupling between filter tube and absorption tube, made of stainless steel.
5.1.5 Absorption tube, made of glass, with an outside diameter of 20 mm and a length of 140 mm.
5.1.6 End piece for absorption tube, made of stainless steel.
...