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1、 Reference number ISO 13478:2007(E) ISO 2007 INTERNATIONAL STANDARD ISO 13478 Second edition 2007-08-15 Thermoplastics pipes for the conveyance of fluids Determination of resistance to rapid crack propagation (RCP) Full-scale test (FST) Tubes en matires thermoplastiques pour le transport des fluides
2、 Dtermination de la rsistance la propagation rapide de la fissure (RCP) Essai grandeur nature (FST) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduct
3、ion or networking permitted without license from IHS -,-,- ISO 13478:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and
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6、und, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2007 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 mi
7、crofilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO
8、 2007 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 13478:2007(
9、E) ISO 2007 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references. 1 3 Terms and definitions. 1 4 Symbols. 2 5 Principle. 2 6 Test parameters 3 7 Materials 3 8 Apparatus 3 9 Test-pipe preparation. 7 10 Conditioning and backfill. 7 11 Test procedure 8 12
10、Validity of results 8 13 Test report . 9 Annex A (normative) Determination of critical pressure (or hoop stress). 10 Annex B (normative) Determination of critical temperature 13 Bibliography. 14 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=
11、IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 13478:2007(E) iv ISO 2007 All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of n
12、ational 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. Inter
13、national 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. International Standards are drafted in accordance with the
14、 rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by
15、 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 13478 was prepared by Technical Committee ISO
16、/TC 138, Plastics pipes, fittings and valves for the transport of fluids, Subcommittee SC 5, General properties of pipes, fittings and valves of plastic materials and their accessories Test methods and basic specifications. This second edition cancels and replaces the first edition (ISO 13478:1997),
17、 which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO
18、13478:2007(E) ISO 2007 All rights reserved v Introduction Test methods that measure the resistance of internally pressurized plastics pipes to rapid fracture propagation (RCP) have been standardized: ISO 13477 1 and this International Standard. The S4 method specified in ISO 13477 utilizes short len
19、gths of pipe to determine a critical RCP pressure or temperature for the pipe. Longer pipes up to 20 m in length are the basis of this full-scale test (FST) method for measurement of these critical parameters. On the one hand, the S4 method uses internal baffles to prevent rapid decompression of the
20、 internal test pressure, thus ensuring that the high-speed crack tip is exposed to the full pipe pressure throughout the test. The FST, on the other hand, has no baffles installed and is more related to field service. The crack tip is subjected to a reducing pressure by decompression effects as the
21、crack propagates. This arrangement reflects the RCP mode of failure of long pipelines and is assumed to be the reference test method. The critical RCP values derived from each test are different but can be correlated experimentally. A mathematical equation for correlation has been developed for poly
22、ethylene (PE) pipes (see ISO 13477). Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- Copy
23、right International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 13478:2007(E) ISO
24、2007 All rights reserved 1 Thermoplastics pipes for the conveyance of fluids Determination of resistance to rapid crack propagation (RCP) Full-scale test (FST) 1 Scope This International Standard specifies a full-scale test (FST) method for determining the arrest or propagation of a crack initiated
25、in a thermoplastics pipe at a specified temperature and internal pressure. The method is also suitable for the determination of defined critical pressure, critical stress and critical temperature parameters. It is applicable to the assessment of the performance of thermoplastics pipes intended for t
26、he supply of gases or liquids. In the latter case, air could also be present in the pipe. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition
27、 of the referenced document (including any amendments) applies. ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the conveyance of fluids Determination of the resistance to internal pressure Part 1: General method ISO 3126, Plastics piping systems Plastics components Determination of di
28、mensions ISO 11922-1, Thermoplastics pipes for the conveyance of fluids Dimensions and tolerances Part 1: Metric series 3 Terms and definitions For the purposes of this International Standard, the terms and definitions given in ISO 11922-1 and the following apply. 3.1 critical pressure pc highest cr
29、ack-arrest pressure below the lowest crack-propagation pressure 3.2 critical hoop stress c highest crack-arrest hoop stress below the lowest crack-propagation hoop stress 3.3 critical temperature Tc lowest crack-arrest temperature above the highest crack-propagation temperature Copyright Internation
30、al Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 13478:2007(E) 2 ISO 2007 All rights reserved 3.4 crack arr
31、est event characterized by the length of the longest crack that is less than or equal to 90 % of the length of the test pipe 3.5 rapid crack propagation RCP event characterized by the length of the longest crack that is greater than 90 % of the length of the test pipe 4 Symbols p test pressure, in b
32、ar 1) pc critical pressure, in bar 1) c critical hoop stress, in megapascals (MPa) Tc critical temperature, in degrees Celsius (C) dem mean outside diameter of test pipe, in millimetres D average of the mean outside diameters, dem, of the pipe sections, in millimetres et mean wall thickness of the t
33、est pipe along the (main) crack, in millimetres. 5 Principle A thermoplastics pipe, maintained at a specified temperature and containing a fluid at a specified test pressure, is subjected to an impact designed to initiate a crack. The crack can then arrest within a short distance or continue to prop
34、agate at high speed along the pipe. The test temperature and test pressure are as defined in the referring standard and are related to the intended operating conditions. The pressurizing fluid is identical to that used in the intended application, or else is a substitute fluid, e.g. air or nitrogen,
35、 which gives equivalent results. The test simulates the performance of a buried pipe in service under conditions which do not retard the rate of decompression of the pressurizing fluid through any fracture. The pipe is subsequently examined to determine whether arrest or propagation of the crack has
36、 occurred. From a series of such tests at different pressures but at a constant temperature, a critical pressure or critical stress for crack propagation can be determined (see Annex A). Similarly, by testing at a series of temperatures while maintaining a constant pressure or hoop stress, the criti
37、cal temperature for RCP can be determined (see Annex B). 1) 1 bar = 0,1 MPa = 105 Pa; 1 MPa = 1 N/mm2. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reprod
38、uction or networking permitted without license from IHS -,-,- ISO 13478:2007(E) ISO 2007 All rights reserved 3 6 Test parameters It is assumed that the following parameters will be set by the referring product standard: a) the diameter(s) and series of the pipe(s) to be tested; b) the pressurizing f
39、luid (7.4), e.g. gas, water, water plus air or nitrogen; c) the test pressure(s); d) the test temperature(s). 7 Materials 7.1 Methylated spirits or ethanol, for use as a cooling fluid (see 8.4.3). 7.2 Solid carbon dioxide, for use as a cooling agent (see 8.4.3). 7.3 Washed gravel, with a size range
40、of 20 mm to 40 mm diameter (see Clause 10). 7.4 Pressurizing fluid, which shall be as specified in the referring standard. NOTE 1 It is satisfactory to use nitrogen or air as the pressurizing fluid instead of natural gas, as the measured pressure for rapid crack propagation (RCP) will be only slight
41、ly less than that obtained with natural gas. The decompression speed (velocity of sound) at 0 C of nitrogen and air is 337 m/s and 334 m/s, respectively, compared with approximately 430 m/s for natural gas. NOTE 2 In water-pipeline systems, which contain water only, the phenomenon of crack propagati
42、on is unlikely to occur. However, when entrained air bubbles or air pockets are present, it is possible. It is usual to test with between 5 % and 10 % by volume of air in the water to determine the resistance to crack propagation. A test on water pipe using 100 % gas, air or nitrogen is more likely
43、to result in RCP and therefore will be expected to give a pessimistic result (also see Reference 2 for RCP testing of pipes filled or partially filled with water). 8 Apparatus 8.1 Temperature-controlled trough, capable of accommodating the overall pipe length normally of 14 m to 20 m (also see Claus
44、e 9). The trough shall have means for maintaining the temperature specified by the referring standard to within 1,5 C along the whole test pipe length. The temperature may be controlled by recirculation of water or air around the test pipe (see Figure 1). The temperature shall be monitored at interv
45、als along the test length. If necessary, the water shall contain antifreeze to avoid ice build-up around the test pipe. NOTE Temperature monitoring along the test length at intervals not exceeding 3 m and around the pipe at the 3 oclock and 9 oclock positions has been found to be satisfactory. Copyr
46、ight International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 08/18/2007 03:11:30 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 13478:2007(E) 4 ISO 2007 All rights reserv
47、ed Dimensions in millimetres Key lt test length (overall pipe length, l, 14 m to 20 m) 1 steel pipe reservoir 2 gravel 3 required butt-fusion joints 4 initiation ring 5 cooling trough 6 pneumatic piston 7 blade 8 end cap Figure 1 Example of test facility for full-scale rapid crack propagation 8.2 St
48、eel-pipe reservoir, connected to the test pipe at one end of the trough. The steel pipe shall have a bore diameter greater than or equal to the test-pipe bore diameter. The pipe reservoir shall have a minimum length of twice that of the test pipe and a minimum volume of three times that of the test pipe. Axial alignment of the reservoir with the test pipe is preferred. 8.3 Pressurization equipment, for pressuri