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1、STD-ISO b24b-ENGL 1995 W 4853703 07bb9LL bb3 W INTERNATIONAL STANDARD IS0 6246:1995 TECHNICAL CORRIGENDUM 1 Published 1998-1 1-1 5 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION - ME)(IIYHAPOnHAR OPiAHM3AUMR no CTAH!J4PTM3AUMM ORGANISATION INTERNATIONALE DE NORMALISATION Petroleum products - Gum con
2、tent of light and middle distillate fuels - Jet evaporation method TECHNICAL CORRIGENDUM 1 Produits ptroliers - Teneur en gommes des distillats lgers et moyens - Methode dvaporation au jet RECTIFICATIF TECHNIQUE 1 Technical Corrigendum 1 to International Standard IS0 6246:1995 was prepared by Techni
3、cal Committee ISOTTC 28, Petroleum products and lubricants. This material is reproduced from IS0 documentc under International Organization for Standardization (ISO) Copyright License Number IHS/ICC/l996. Not for resale. No part of these IS0 documents may be reproduced in any form, electronic retrie
4、val system or othetwise, except as allowed in the copyright law of the country of use, or with the prior written consent of IS0 (Case postale 56, 12 I I Geneva 20, Switzerland, Fax + 4 1 22 734 10 79), IHS or the I S 0 Licensors members. Page 4 Subclause 7.1 Replace the text of note 4 with the follo
5、wing text: “A total reading on a flow indicator (calibrated under ambient conditions) corresponding to 600 ml/s f 90 ml/s at each outlet will ensure a flowrate of 1 O00 mlls +_ 150 mlls at a temperature of 155 O C +_ 5 OC, provided that the back pressure across the flow indicator is not greater than
6、 1 kPa.“ ICC 75.160.20 Ref. No. IS0 6246:1995/Cor.l:1998(E) O IS0 1998 Printed in Switzerland COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services = 485390
7、3 Ob25632 LTb = I NTE RNAT I O NAL STANDARD IS0 6246 Second edition 1995-08-1 5 Petroleum products - Gum content of light and middle distillate fuels - Jet evaporation method Produits ptroliers - Teneur en gommes des distillats lgers et moyens - Mthode dvaporation au jet Reference number IS0 6246:19
8、95(E) COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services Y851903 0625b33 032 IS0 6246:1995(E) Foreword IS0 (the International Organization for Standardiz
9、ation) 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
10、 represented 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 S
11、tandards 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 6246 was prepared by Technical Committee ISO/TC 28, Petroleum produ
12、cts and lubricants. This second edition cancels and replaces the first edition (IS0 6246:1981), which has been technically revised. Annex A forms an integral part of this International Standard. Q IS0 1995 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
13、 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 CH-1 21 1 Genve 20 . Switzerland Printed in Switzerland II COPYRIGHT Internationa
14、l Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services - 4851903 0625634 T79 INTERNATIONAL STANDARD Q IS0 IS0 6246:1995(E) Petroleum products - Gum content of light and middle dis
15、tillate fuels - Jet evaporation method WARNING - The use of this International Standard may involve hazardous materials, operations and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to es
16、tablish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 1 Scope This International Standard.specifies a method for the determination of the existent gum content of aviation fuels, and the gum content of motor gasolines or other volatile
17、 distillates in their finished form, and at the time of test. For non-aviation fuels, a procedure for the determi- nation of the heptane-insoluble portion of the residue is also described. CAUTION - This method is not intended for the testing of gasoline components, particularly those with a high pe
18、rcentage of low-boiling unsaturated compounds, as they may cause explosions during evaporation. NOTE 1 The true significance of this test method for de- termining gum in motor gasoline is not firmly established. It has been proved that high gum content can cause induction-system deposits and stickin
19、g of intake valves, and in most instances it can be assumed that low gum content will ensure absence of induction-system difficulties. The user should, however, realize that the test is not of itself correlative to induction-system deposits. The primary pur- pose of the test, as applied to motor gas
20、oline, is the meas- urement of the oxidation products formed in the sample prior to or during the comparatively mild conditions of the test procedure. Since many motor gasolines are purposely blended with non-volatile oils or additives, the heptane ex- traction step is necessary to remove these from
21、 the evap oration residue so that the deleterious material, gum, may be determined. With respect to aviation turbine fuels, large quantities of gum are indicative of contamination of fuel by higher boiling oils or particulate matter and generally reflect poor handling practices in distribution downs
22、tream of the refinery. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All standards are subject to revision, and parties to
23、 agreements based on this International Standard are encouraged to investigate the possibility of applying the most re- cent editions of the standards indicated below. Members of IEC and IS0 maintain registers of cur- rently valid International Standards. IS0 3 1 70:1988, Petroleum liquids - Manual
24、sampling. IS0 3 1 7 1 :I 988, Petroleum liquids - Automatic pipe- line sampling. IS0 3696:1987, Water for analytical laboratory use - Specification and test methods. IS0 4788: 1980, Laboratory glassware - Graduated measuring cylinders. IS0 6353-2:1983, Reagents for chemical analysis - Part 2: Specif
25、ications - First series. IS0 6353-3:1987, Reagents for chemical analysis - Part 3: Specifications - Second series. 1 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Han
26、dling Services 48511903 0625635 705 IS0 6246:1995(E) Q IS0 3 Definitions 6 Apparatus For the purposes of this International Standard, the following definitions apply. 0,l mg. 3.1 fuels, without any further treatment. 6.1 Balance, capable of weighing to an accuracy of existent gum: Evaporation residu
27、e O f aviation 6.2 trated in figure 1, individually permanently marked. Beakers, 100 ml of capacity, tall form, as illus- 3.2 evaporation residue: Material that remains af- ter controlled heating under a flow or air or steam. 3.3 gum content, unwashed (non-aviation fuel): Evaporation residue of the
28、product under test, without any further treatment. 3.4 gum content, solvent-washed (non-aviation fuel): Residue remaining after the evaporation residue has been washed with heptane and the washings discarded. 4 Principle NOTE 2 It is expedient to arrange the beakers in sets, the number in each set b
29、eing the number of beaker wells in the evaporating bath. The lowest-mass beaker in each set should be reserved for use as the tare. 6.3 Cooling vessel, tightly covered, for cooling the beakers before weighing. NOTE 3 commended. If a desiccator is used, a drying agent is not re- 6.4 Evaporation bath,
30、 either a solid metal block bath or a liquid bath, electrically heated and con- structed in accordance with the general principles shown in figure 1, having wells and jets for two or more beakers. A fneasured test Portion of fuel is evaporated Under controlled conditions O f temperature and flow O f
31、 air or steam. The resulting residue is weighed, and may be subject to further treatment by solvent washing and further weighing. The rate of air/steam flow at the temperature of test from each outlet jet when fitted with the conical adaptors shall be 1 O00 ml/s f 150 ml/s. A liquid bath, if used, s
32、hall be filled to within 25 mm of the top with a suitable liquid. Maintain the bath temperature either by means of thermostatic controls or by reflux- ing liquid of suitable composition. 5 Reagents and materials 6.5 Flow indicator, capable of indicating a total flow of air or steam equivalent to 1 O
33、00 mils for each out- During the analysis, unless otherwise stated, use only let jet. reagents specified in IS0 6353-2 and IS0 6353-3 if listed there; if not, use reagents of recognized ana- 6.6 Sintered glass filter funnel, capacity 150 ml, lytical grade. Water where specified, shall be of a with a
34、 maximum pore diameter between 150 pm and quality equivalent to grade 3 of IS0 3696. 250 pm. 5.1 Heptane, CH3(CH2)5CH3. 5.2 Toluene, CsH5CH3. 5.3 Acetone, CH3COCH3. 6.7 Steam superheater, gas-fired or electrically heated, capable of delivering to the bath inlet the re- quired amount of steam at 232
35、“C f 3 O C . 6.8 Two thermometers, conforming to the require- ments in annex A. 5s4 Gum a mixture Of equal volumes Of 6.9 Graduated cylinders, capacity 50 ml or 100 ml toluene (5.2) and acetone (5.3). and 2 litres, conforming to the requirements of IS0 4788. 5.5 Air supply, filtered, at a gauge pres
36、sure of not greater than 34,5 kPa. 6.10 Forceps, stainless steel, spade-ended. 5.6 Steam supply, free of oily residue and at a 6.11 Oven, capable of being maintained at 150 O C f 2 “C. pressure of not less than 34,5 kPa. 2 COPYRIGHT International Organization for Standardization Licensed by Informat
37、ion Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services D 4851903 Ob25636 841 D uw CL 0 0 IS0 6246:1995(E) Dimensions in millimetres L W c Lc O .- 2 s u) l n O u l L O C d + + O U I z1 L .- a Y O Y z 4 + W E al Y Ln + m 8 a O L 5 al vi
38、 + Figure 1 - Apparatus for determining gum content by jet evaporation 3 COPYRIGHT International Organization for Standardization Licensed by Information Handling Services COPYRIGHT International Organization for Standardization Licensed by Information Handling Services IS0 6246:1995(E) rn 4853903 0
39、625637 788 rn 0 IS0 7 Assembly of air-jet apparatus 7.1 Assemble the air-jet apparatus as shown in fig- ure 1. With the apparatus at room temperature, adjust the flow of air to a rate of 600 mils at one of the outlets, with the remaining conical adaptors in pos- ition. Check the other outlets indivi
40、dually under the same conditions for uniform air flowrate within the range of 600 ml/s f 90 ml/s. NOTE 4 A total reading on a flow indicator (calibrated under ambient conditions) corresponding to 600 ml/s f 90 ml/s at each outlet will ensure a flowrate of 1 O00 ml/s f 150 ml/s at a temperature of 15
41、5 “C f 5 “C, provided that the pressure at the outlet of the flow indicator is not greater than 345 kPa. 7.2 In order to set the apparatus in operation, heat the bath until the temperature reaches 162 O C , and then introduce air into the apparatus until the reading established in accordance with 7.
42、1 is obtained on the flow indicator. Measure the temperature in each well with the thermometer (6.8) placed with the bulb rest- ing on the bottom of a beaker (6.2) in the well. Do not use any well having a temperature that differs from 155 “C by more than 5 “C for standard tests. 8 Assembly of steam
43、-jet apparatus 8.1 figure 1. Assemble the steam-jet apparatus as shown in 8.2 In order to set the apparatus in operation, heat the bath until the temperature reaches 232 “C. Oper- ate the superheater, and slowly admit dry steam into the apparatus until a flowrate of 1 O00 ml/s f 150 ml/s per outlet
44、is obtained. Regulate the tem- perature of the bath within the range 239 “C f 7 “C and that of the superheater to provide a well tem- perature of 232 “C f 3 “C. Measure the temperature with the thermometer (6.8) placed with the bulb rest- ing on the bottom of a beaker (6.2) in the well. Do not use a
45、ny well having a temperature that differs from 232 O C by more than 3 “C for standard tests. 8.3 Calibrate the flowmeter by successively con- densing the steam flow from each outlet and weigh- ing the total quantity of water recovered. To accomplish this, attach a copper tube to a steam out- let jet
46、 and extend the tube into a 2 litre cylinder (6.9) that has been filled with crushed ice and then weighed. Exhaust the steam into the cylinder for ap- proximately 60 s. Adjust the position of the cylinder so that the end of the copper tube is immersed in the water to a depth of less than 50 mm to pr
47、event ex- cessive back-pressure. Weigh the cylinder. The gain in mass represents the amount of steam condensed. Calculate the steam flowrate, S, as follows: S = (Q - m,) 1 OOO/kt where S is the flowrate of the steam, in millilitres per second, at 232 “C; Q is the mass, in grams, of the cylinder with
48、 the condensed steam; m, k is the mass, in grams, of the cylinder and ice; is the mass (0,434 g) of 1 O00 ml of steam at 232 “C at atmospheric pressure; is the condensing time, in seconds. t 8.4 Adjust the apparatus to give a steam flowrate of 1 O00 ml/s for the outlet under test. Check the re- main
49、ing outlets for uniform steam flow. Make necessary changes to individual outlets if the rate varies by more than 150 ml of steam per second, re- cord the flowmeter reading and use this setting for subsequent testing. 9 Samples and sampling Samples for testing by the procedures described in this International Standard shall be taken by the pro- cedure described in IS0 3170, IS0 3171 or an equiv- alent national standard. 10 Procedure 10.1 Wash the beakers (6.2) including the tare, with the gum solvent (5.4) until free of gum. Rinse thor- oughly with water and immerse in deterg
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