1、BRITISH STANDARD BS EN ISO 11541:2002 Incorporating Amendment No. 1 to BS 3156-11.6:1997 (renumbers the BS as BS EN ISO 11541:2002) Natural gas Determination of water content at high pressure The European Standard EN ISO 11541:2002 has the status of a British Standard ICS 75.060 BS EN ISO 11541:2002
2、 This British Standard, having been prepared under the direction of the Sector Board for Materials and Chemicals, was published under the authority of the Standards Board and comes into effect on 15 July 1997 BSI 3 March 2003 ISBN 0 580 27537 X National foreword This British Standard is the official
3、 English language version of EN ISO 11541:2002. It is identical with ISO 11541:1997. The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis, which has the responsibility to: aid enquirers to understand the text; present to the responsible in
4、ternational/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to
5、its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electron
6、ic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This
7、 document comprises a front cover, an inside front cover, the EN title page, the EN foreword page, the ISO title page, pages ii to iv, pages 1 to 8, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issu
8、ed since publication Amd. No. Date Comments 14241 3 March 2003 Renumbers BS 3156-11.6:1997 as BS EN ISO 11541:2002EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11541 November 2002 ICS 75.060 English version Natural gas Determination of water content at high pressure (ISO 11541:1997) Gaz n
9、aturel Dosage de leau haute pression (ISO 11541:1997) Erdgas Bestimmung des Wassergehaltes unter hohem 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 giv
10、ing 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 versio
11、ns (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, Czec
12、h Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Management Centre:
13、 rue de Stassart 36, B-1050 Brussels 2002 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11541:2002 EEN ISO 11541:2002 BSI 3 March 2003 Foreword The text of ISO 11541:1997 has been prepared by Technical Committee ISO/TC 193, N
14、atural 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 conflicti
15、ng 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, G
16、reece, 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 Stand
17、ards are listed in Annex ZA (normative).EN ISO 11541:2002EN ISO 11541:2002 BSI 3 March 2003 ii Contents Page Foreword iii 1S c o p e 1 2 Normative reference 1 3 Principle 1 4R e a g e n t s a n d m a t e r i a l s 1 5 Apparatus 1 6 Procedure 2 7 Expression of results 3 8 Test report 4 Figure 1 Press
18、ure vessel with filter and absorption tube 5 Figure 2 Schematic diagram of test apparatus 6 Figure 3 Schematic diagram of test apparatus with parallel sampling 7EN ISO 11541:2002 BSI 3 March 2003 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of natio
19、nal standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. Internati
20、onal organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committ
21、ees 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 ISO 11541 was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee SC 1, Analysis of natural ga
22、s. Descriptors: Natural gas, gas analysis, determination of content, wateriv blankEN ISO 11541:2002 BSI 3 March 2003 1 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
23、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. I
24、t is applicable to sweet natural gas and sour natural gas, containing hydrogen sulfide, with a water concentration of 10 mg/m 3or more. 1) 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 pen
25、toxide (P 2 O 5 ) 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 s
26、ubject 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 ISO maintain registers of currently valid International Standards. ISO 10715, Natur
27、al gas Sampling guidelines 2) 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
28、 water present in the gas. The absorption of water vapour at pipeline pressure is favoured over absorption at ambient pressure for the following reasons: a) the water vapour partial pressure is high; b) the necessary amount of gas is transmitted in a shorter time. 4 Reagents and materials 4.1 Granul
29、ated 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 wit
30、h 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 5.1 The test apparatus consists of the following components (see Figure 1, Figure 2 and Figure 3): 5.1.1 Pressure vessel body 5.1.2 En
31、d 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
32、 a length of 140 mm. 1) In this International Standard, all volumes are expressed at 288,15 K and 101,325 kPa. 2) To be published.EN ISO 11541:2002 2 BSI 3 March 2003 5.1.6 End piece for absorption tube, made of stainless steel. 5.1.7 Plugs for absorption tube, made of stainless steel or acrylic pla
33、stic. 5.1.8 Needle valve, designed as a shut-off valve which will produce a slow pressure increase in the absorption tube, with a transfer line linking it to the sample probe and connector linking it to the pressure vessel inlet. 5.1.9 Pressure vessel, capable of accommodating the filter tube and th
34、e absorption tube. WARNING The pressure vessel shall be designed and have been tested for the pressure for which it will be used. Appropriate national safety regulations for pressure vessels and other equipment shall be observed. 5.1.10 Connector, for the pressure vessel outlet. 5.1.11 Manometer, fo
35、r the appropriate pressure range. 5.1.12 Outlet needle valve, for venting, made of stainless steel. 5.1.13 Gas flow meter, for a maximum flow rate of 10 m 3 /h. 5.1.14 Thermometer, incorporated in the flow meter outlet. 5.1.15 Barometer 5.1.16 Vent line 5.1.17 Heater 5.1.18 Sample probe valve 5.1.19
36、 Manifold 5.2 The pressure vessel, the two needle valves, the manometer and all piping and fittings shall be designed for the maximum test pressure. If sour gas is measured, the material used shall be suitable for sour-gas service. The inside length of the pressure vessel shall be such that the filt
37、er tube, the coupling and the absorption tube will not be separated by a sudden pressure increase. 5.3 The connectors at the inlet and the outlet of the pressure vessel shall be easy to attach and to release. 6 Procedure 6.1 Preparation of the absorption tube Fill the absorption tube (5.1.5) with gr
38、anulated phosphorus pentoxide (4.1). The ends of the tube shall be flocked with silica wool (approx. 2 cm) such that no cavities remain. Close the absorption tube with marked plugs (5.1.7). 6.2 Preparation of the filter tube Fill the filter tube (5.1.3) with silica wool. 6.3 Preparation of the test
39、apparatus 6.3.1 Initial weighing of the tubes Weigh the absorption tube with the marked plugs (= m 1 ) and also weigh the filter tube together with the coupling (5.1.4) immediately before assembly. 6.3.2 Assembly of the pressure vessel Remove the marked plugs from the absorption tube and set them as
40、ide. Mount the end piece (5.1.6) on one end of the absorption tube. Join the other end of the absorption tube to the filter tube by means of the coupling. Insert the tube assembly into the pressure vessel body (5.1.1) with the open end of the filter tube at the inlet side. Then close the pressure ve
41、ssel. Keep the marked plugs in a dessicator when not in use.EN ISO 11541:2002 BSI 3 March 2003 3 6.3.3 Preparation of the sample probe The sample probe shall be clean and dry. The inlet needle valve with the connector for the pressure vessel inlet shall be mounted. 6.3.4 Installation of the gas flow
42、 meter Join the connector for the pressure vessel outlet (5.1.10), the manometer (5.1.11) and the inlet needle valve (5.1.8) by high-pressure tubing. Join the flow meter (5.1.13) and the thermometer (5.1.14) to the outlet needle valve (5.1.12) and the vent line (5.1.16). 6.3.5 Installation of the te
43、st apparatus Connect the pressure vessel (5.1.9) to the sample probe valve (5.1.18) and the flow meter using the connectors (5.1.8, 5.1.10). Purge the sample probe upstream of the pressure vessel with sample gas. 6.4 Sampling See ISO 10715 for general guidelines on sampling. Make sure that the inlet
44、 and outlet valves (5.1.8, 5.1.12) are closed and the sample probe valve (5.1.18) is opened. Open the inlet needle valve (5.1.8) carefully and pressurize the test apparatus. Inspect the test apparatus for leaks. Open the outlet needle valve (5.1.12) carefully and adjust the flow to 2 m 3 /h to 3 m 3
45、 /h. During sampling, record the atmospheric pressure and gas temperature and monitor the gas flow rate. After a sample of 1,5 m 3to 3 m 3has been passed through the apparatus, close the inlet needle valve (5.1.8) and depressurize the test apparatus. Record the quantity of gas which has passed throu
46、gh the apparatus (= V 0 ), as measured by the flow meter (5.1.13). Do not exceed one-half of absorption tube capacity or the test may be invalidated. When sampling in a humid environment, special care shall be taken to avoid condensation on the tubes. The maximum water concentration will depend on t
47、he actual pressure and temperature of the gas. The temperature of the sampling equipment and the test apparatus needs to be higher than the water dew point at the sampling pressure. If condensation should occur, thus invalidating the test data, heat the test apparatus to a temperature above the hydr
48、ocarbon dew point before making additional measurements. 6.5 Second weighing of the tubes Remove the pressure vessel from the test apparatus and open it. Seal the absorption tube immediately after opening the pressure vessel, using the two marked plugs utilized for the initial weighing, and weigh ag
49、ain the absorption tube (= m 2 ). Weigh again the filter tube together with the coupling. If the mass of the filter tube has increased by more than 5 mg/m 3 , determine visually or by chemical analysis whether impurities have penetrated to the absorption tube. If penetration has occurred, the measurement is invalid. Verify that the P 2 O 5packing in the absorption tube is still complete and that the P 2 O 5moisture indicator indicates that water has entered only the first
