1、BRITISH STANDARDBS EN 15471:2007Liquefied petroleum gases Determination of dissolved residues High-temperature gravimetric methodThe European Standard EN 15471:2007 has the status of a British StandardICS 75.160.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54
2、g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 15471:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978 0 580 56658 5National foreword
3、This British Standard is the UK implementation of EN 15471:2007.The UK participation in its preparation was entrusted to Technical Committee PTI/15, Natural gas and gas analysis.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does no
4、t purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NOR
5、MEN 15471November 2007ICS 75.160.10English VersionLiquefied petroleum gases - Determination of dissolved residues- High-temperature gravimetric methodGaz de ptrole liqufis - Dtermination des rsidusdissous - Mthode gravimtrique haute tempratureFlssiggas - Bestimmung der gelsten Rckstnde -Gravimetrisc
6、hes HochtemperaturverfahrenThis European Standard was approved by CEN on 7 October 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists
7、 and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsi
8、bility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland,
9、 Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart
10、, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15471:2007: EEN 15471:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative reference 4 3 Terms and definitions .4 4 Principle4 5 Reagents.4 6 Apparatus .5
11、7 Sampling.6 8 Procedure .6 8.1 Sampling.6 8.2 Evaporation of the LPG.7 8.3 Jet evaporation procedure7 9 Calculation8 10 Expression of results 8 11 Precision.8 11.1 General8 11.2 Repeatability, r .8 11.3 Reproducibility, R 9 Bibliography 10 EN 15471:2007 (E) 3 Foreword This document (EN 15471:2007)
12、has been prepared by Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”, the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publication of an
13、identical text or by endorsement, at the latest by May 2008, and conflicting national standards shall be withdrawn at the latest by May 2008. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held res
14、ponsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, Fra
15、nce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. EN 15471:2007 (E) 4 1 Scope This Standard specifies a method, for determining the resid
16、ual matter in liquefied petroleum gases (LPG), which remains after evaporation at 105 C. This material represents those products deposited in car LPG vaporizers that are subject to a temperature equal to or greater than the boiling temperature of water. The range of determination extends from 50 mg/
17、kg to 100 mg/kg. Higher concentrations can be determined by adjusting the sample size. The precision data of the method have been determined from 20 mg/kg to 100 mg/kg, with samples amount from 100 g to 50 g. This method has been developed as a potential replacement of the commonly used method EN IS
18、O 13757 1, The advantages of the method are that a small quantity of LPG (100 ml) is required. NOTE An alternative European Standard, EN 15470 2, with the same scope, specifies a gas chromatography method with slightly better fidelity. WARNING Use of this method involves hazardous materials and oper
19、ations. It is the responsibility of the user to establish appropriate safety and health precautions. All handling must be performed in a fume hood. 2 Normative reference The following referenced documents are indispensable for the application of this document. For dated references only the edition c
20、ited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 4257, Liquefied petroleum gases - Method of sampling (ISO 4257:2001) 3 Terms and definitions For the purposes of this document, the following term and definition applies. 3.
21、1 liquefied petroleum gas (LPG) petroleum gas that can be stored and/or handled in the liquid phase under moderate conditions of pressure and at ambient temperature, consisting predominantly of propane, butanes, with small proportions of propene, butenes and pentanes/pentenes 4 Principle A known mas
22、s of LPG is sampled and concentrated by evaporation. The concentrate is transferred into a beaker of 100 ml capacity and then evaporated by jet evaporation under controlled conditions of temperature and airflow. The oily residue remaining after this procedure is cooled and weighed. 5 Reagents 5.1 n-
23、heptane, analytical grade. 5.2 2-propanol, technical grade, for the cooling bath. 5.3 Solid carbon dioxide, for the cooling bath. EN 15471:2007 (E) 5 5.4 Air, supply of filtered air at a pressure not more than 34,5 kPa. 5.5 propanone (acetone) 6 Apparatus 6.1 Sample cylinder, made of stainless steel
24、, fitted with two stainless steel valves conforming to EN ISO 4257 and having a maximum service pressure of 3 MPa and a minimum capacity of 1 l. This cylinder is used to sample the LPG, of which the dissolved residues are to be determined. 6.2 In-line filter support, made of stainless steel and for
25、use at suitable high pressure. 6.3 Filter discs, plain membrane with nominal pore dimension of 0,8 m. 6.4 Cooling coil, made by coiling 4 m of stainless steel tube of external diameter 6 mm and internal diameter 4 mm onto a mandrel of a diameter of approximately 50 mm and fitted with the necessary c
26、onnections (see 3 in Figure 2). 6.5 Cooling bath, comprising a Dewar flask, three-quarters filled with an appropriate liquid, e.g. 2-propanol (5.2) cooled with solid carbon dioxide, to achieve a temperature of about - 60 C. 6.6 Beaker, made of glass, with a capacity of 1 l. 6.7 Ebullition regulating
27、 rod, made of glass and a length of about 28 cm. 6.8 Beaker, made of glass and with a capacity 100 ml. 6.9 Balances 6.9.1 For weighing the sample cylinder (6.1), balance with a range of 10 kg minimum, accurate to within 1 g or better. 6.9.2 For weighing the beaker (6.8), balance with a range of 200
28、g, accurate to within 0,1 mg or better. 6.10 Cabinet drier, suitable for the preparation of the 100 ml beaker (6.8). 6.11 Desiccator. 6.12 Apparatus, for determining evaporation residues by air jet evaporation according to Figure 1 (for further information see ASTM D 381 3 ). EN 15471:2007 (E) 6 Key
29、 1. dry air supply 2. dry and clean steam supply 3. thermometer and well (optional) 4. thermometer 5. flow indicator 6. removable adaptor 7. heating block 8. thermo-regulator Figure 1 Apparatus for determining oily residues by jet evaporation 7 Sampling Samples shall be taken as described in EN ISO
30、4257 and/or in accordance with the requirements of national standards or regulations for the sampling of automotive LPG. 8 Procedure 8.1 Sampling Assemble the apparatus, as shown in Figure 2, and operate the following instructions: a) slowly shake the sample cylinder (6.1) containing the LPG to be a
31、nalysed, in order to mix the contents; b) connect the lower valve of the sample cylinder to the in-line filter (6.2); c) purge and fill the in-line filter and the cooling coil with the LPG to be analyzed; d) close the lower valve of the sample cylinder; e) disconnect the in-line filter from the samp
32、le cylinder and weigh the sample cylinder to obtain its mass m1in grams; f) reconnect the sample cylinder to the purged in-line filter and cooling coil; EN 15471:2007 (E) 7 g) position the 1 l beaker (6.6) and open the lower valve of the sample cylinder to obtain a steady flow of LPG sample into the
33、 beaker, until a mass of approximately 250 g is obtained; h) close the lower valve of the sample cylinder; i) disconnect the in-line filter from the sample cylinder and weigh the sample cylinder once more to obtain the post sample cylinder mass m2in grams. The test sample mass, ms, in grams, is dete
34、rmined by subtraction: 21 mmms = (1) 8.2 Evaporation of the LPG Place the beaker with the sample (see 8.1) into an explosion-proof hood. Leave to evaporate until there is no visible volume of liquid left in the beaker. Key 1. sample cylinder with two valves (6.1) 2. in-line filter support (6.2) 3. s
35、tainless steel cooling coil (see 6.4) 4. Dewar flask filled as stipulated in 6.5 5. 1 l beaker (6.6) 6. ebullition regulating rod (6.7) 7. earthing Figure 2 Sampling assembly 8.3 Jet evaporation procedure The 100 ml beaker (6.8) is washed/rinsed with acetone (5.5) and distilled water and then dried
36、at 105 C for 30 min. EN 15471:2007 (E) 8 When found necessary one may also immerse the beaker in a mildly detergent solution or, for a deeper cleaning action, use an oxidative acid cleaning solution. After a few hours soaking period, rinse with distillated water and dry. After cooling, this 100 ml b
37、eaker is placed in a desiccator (6.11) for 30 min, and then weighed to the nearest 0,1 mg to obtain the mass m3. Rinse the walls of the 1 l beaker (6.6) twice very carefully with approximately 20 ml n-heptane (5.1) each time and transfer the contents into the previously prepared 100 ml beaker. Place
38、 the 100 ml beaker into the jet evaporation apparatus (6.12) as shown in Figure 1 and let the contents evaporate for a period of 30 min at 105 C with an air stream of 18 l/min to 24 l/min. Remove the beaker from the jet evaporation apparatus and place it in a desiccator for between 30 min and 1 h. F
39、inally, weigh the beaker to the nearest 0,1 mg to obtain the mass m4. The difference between this mass and the tare mass of the beaker gives the mass mrof the dissolved residue obtained during the test. ()34 mmmr = (2) where mris the mass, in milligrams, of residue obtained during the test; m3is the
40、 tare mass, in milligrams, of the 100 ml beaker; m4is the mass, in milligrams, of the 100 ml beaker plus residue. 9 Calculation Calculate the dissolved residue of the sample, ER, after evaporation, in milligrams per kilogram, using the following equation: srmmER1000= (3) where mris the mass, in mill
41、igrams, of residue obtained during the test; msis the mass, in grams, of the LPG sample. 10 Expression of results Report the result to the nearest 1 mg/kg. 11 Precision 11.1 General The precision of this method, established during interlaboratory tests relating to LPG samples with oily residue conte
42、nts between 20 mg/kg and 100 mg/kg, and determined on the basis of statistical examination of interlaboratory test results 4, is as follows: 11.2 Repeatability, r The difference between two test results obtained by the same operator with the same apparatus under constant operating conditions on nomi
43、nally identical test material would, in the long run, in the normal and EN 15471:2007 (E) 9 correct operation of the test method, exceed the value as given in Table 1 in only one case in 20 (see Table 2 for further details). 11.3 Reproducibility, R The difference between two single and independent r
44、esults obtained by different operators working in different laboratories on nominally identical test material would, in the long run, in the normal and correct operation of the test method, exceed the value as given in Table 1 in only one case in 20 (see Table 2 for further details). Table 1 Repeata
45、bility and reproducibility r (mg/kg) R (mg/kg) r = 0,081X + 4,25 mg/kg R = 0,204 X + 10,7 mg/kg where X = the average of two results being compared, in mg/kg. Table 2 Calculated precision at different levels Level (mg/kg) r (mg/kg) R (mg/kg) 20 6 15 50 8 21 75 10 26 100 12 31 EN 15471:2007 (E) 10 Bi
46、bliography 1 EN ISO 13757:1996, Liquefied petroleum gases - Determination of oily residues - High-temperature method (ISO 13757:1996) 2 EN 15470, Liquefied petroleum gases - Determination of dissolved residues - High temperature Gas chromatographic method 3 ASTM D381 Standard test method for Gum Con
47、tent in Fuels by Jet Evaporation 4 EN ISO 4259, Petroleum products - Determination and application of precision data in relation to methods of test (ISO 4259:2006) blankBS EN 15471:2007BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is the independent national body responsi
48、ble for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.RevisionsBritish Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments
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