1、November 2007DEUTSCHE NORM English price group 11No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 23.040.20!$JJ“1393925
2、www.din.deDDIN EN ISO 13478Thermoplastics pipes for the conveyance of fluids Determination of resistance to rapid crack propagation (RCP) Full-scale test (FST) (ISO 13478:2007)English version of DIN EN ISO 13478:2007-11Rohre aus Thermoplasten fr den Transport von Fluiden Bestimmung des Widerstandes
3、gegenber schneller Rissfortpflanzung (RCP) Praxistest (FS-Prfung) (ISO 13478:2007)Englische Fassung DIN EN ISO 13478:2007-11SupersedesDIN EN ISO 13478:1997-09www.beuth.deDocument comprises 20 pagesDIN EN ISO 13478:2007-11 2 National foreword This standard has been prepared by Technical Committee ISO
4、/TC 138 “Plastics pipes, fittings and valves for the transport of fluids” in collaboration with Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems” (Secretariat: NEN, the Netherlands). The responsible German body involved in its preparation was the Normenausschuss Kunststoff
5、e (Plastics Standards Committee), Technical Committee NA 054-05-02 AA Prfverfahren fr Rohre. The DIN Standards corresponding to the International Standards referred to in clause 2 of the EN are as follows: ISO 1167 DIN EN ISO 1167-1 ISO 3126 DIN EN ISO 3126 Amendments This standard differs from DIN
6、EN ISO 13478:1997-09 as follows: a) The bibliography has been supplemented to include information on the rapid crack propagation (RCP). Previous editions DIN EN ISO 13478: 1997-09 National Annex NA (informative) Bibliography DIN EN ISO 1167-1, Thermoplastics pipes, fittings and assemblies for the co
7、nveyance of fluids Determina-tion of the resistance to internal pressure Part 1: General method DIN EN ISO 3126, Plastics piping systems Plastics components Determination of dimensions EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 13478August 2007ICS 23.040.20 Supersedes EN ISO 13478:1997 En
8、glish VersionThermoplastics pipes for the conveyance of fluids -Determination of resistance to rapid crack propagation (RCP) -Full-scale test (FST) (ISO 13478:2007)Tubes en matires thermoplastiques pour le transport desfluides - Dtermination de la rsistance la propagationrapide de la fissure (RCP) -
9、 Essai grandeur nature (FST)(ISO 13478:2007)Rohre aus Thermoplasten fr den Transport von Fluiden -Bestimmung des Widerstandes gegenber schnellerThis European Standard was approved by CEN on 30 June 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the con
10、ditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists 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
11、 official versions (English, French, German). A version in any other language made by translationunder the responsibility 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 Austr
12、ia, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTE
13、E FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 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 ISO 13478:2007: ERissfortpflanzung (RCP) - P
14、raxistest (FS-Prfung)(ISO 13478:2007)Contents Page 1 2 3 4 5 6 7 8 9 10 11 12 13 EN ISO 13478:2007 (E)2Foreword. 3 Introduction 4 Scope . 5 Normative references . 5 Terms and definitions. 5 Symbols . 6 Principle. 6 Test parameters 7 Materials 7 Apparatus 7 Test-pipe preparation . 11 Conditioning and
15、 backfill. 11 Test procedure 12 Validity of results 12 Test report . 13 Annex A (normative) Determination of critical pressure (or hoop stress). 14 Annex B (normative) Determination of critical temperature 17 Bibliography . 18 Foreword This document (EN ISO 13478:2007) has been prepared by Technical
16、 Committee ISO/TC 138 “Plastics pipes, fittings and valves for the transport of fluids“ in collaboration with Technical Committee CEN/TC 155 “Plastics piping systems and ducting systems” the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard,
17、 either by publication of an identical text or by endorsement, at the latest by February 2008, and conflicting national standards shall be withdrawn at the latest by February 2008. This document supersedes EN ISO 13478:1997. According to the CEN/CENELEC Internal Regulations, the national standards o
18、rganizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal
19、, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 13478:2007 has been approved by CEN as a EN ISO 13478:2007 without any modification. EN ISO 13478:2007 (E)3Introduction Test methods that measure the resistance of internally pressuri
20、zed plastics pipes to rapid fracture propagation (RCP) have been standardized: ISO 134771and this International Standard. The S4 method specified in ISO 13477utilizes short lengths of pipe to determine a critical RCP pressure or temperature for the pipe. Longer pipes up to 20 m in length are the bas
21、is 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 internal test pressure, thus ensuring that the high-speed crack tip is exposed to the full pipe pressure throughout the tes
22、t. 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 crack propagates. This arrangement reflects the RCP mode of failure of long pipelines and is assumed to be the reference tes
23、t 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 polyethylene (PE) pipes (see ISO 13477). EN ISO 13478:2007 (E)41 Scope This International Standard specifies a full-scale test (
24、FST) method for determining the arrest or propagation of a crack initiated 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
25、to the assessment of the performance of thermoplastics pipes intended for the 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,
26、 only the edition cited applies. For undated references, the latest edition 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 metho
27、d ISO 3126, Plastics piping systems Plastics components Determination of dimensions 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
28、in ISO 11922-1 and the following apply. 3.1 critical pressure pchighest crack-arrest pressure below the lowest crack-propagation pressure 3.2 critical hoop stress chighest crack-arrest hoop stress below the lowest crack-propagation hoop stress 3.3 critical temperature Tclowest crack-arrest temperatu
29、re above the highest crack-propagation temperature EN ISO 13478:2007 (E)53.4 crack arrest 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 th
30、at is greater than 90 % of the length of the test pipe 4 Symbols p test pressure, in bar 1)pccritical pressure, in bar1)ccritical hoop stress, in megapascals (MPa) Tccritical temperature, in degrees Celsius (C) demmean outside diameter of test pipe, in millimetres D average of the mean outside diame
31、ters, dem, of the pipe sections, in millimetres etmean wall thickness of the test 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
32、a crack. The crack can then arrest within a short distance or continue to propagate 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
33、the intended application, or else is a substitute fluid, e.g. air or nitrogen, 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 sub
34、sequently examined to determine whether arrest or propagation of the crack has 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 o
35、f temperatures while maintaining a constant pressure or hoop stress, the critical temperature for RCP can be determined (see Annex B). 1) 1 bar = 0,1 MPa = 105Pa; 1 MPa = 1 N/mm2. EN ISO 13478:2007 (E)66 Test parameters It is assumed that the following parameters will be set by the referring product
36、 standard: a) the diameter(s) and series of the pipe(s) to be tested; b) the pressurizing fluid (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 ca
37、rbon dioxide, for use as a cooling agent (see 8.4.3). 7.3 Washed gravel, with a size range 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
38、natural gas, as the measured pressure for rapid crack propagation (RCP) will be only slightly 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. NO
39、TE 2 In water-pipeline systems, which contain water only, the phenomenon of crack propagation 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
40、to crack propagation. A test on water pipe using 100 % gas, air or nitrogen is more likely 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
41、, capable of accommodating the overall pipe length normally of 14 m to 20 m (also see Clause 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 wat
42、er or air around the test pipe (see Figure 1). The temperature shall be monitored at intervals 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 arou
43、nd the pipe at the 3 oclock and 9 oclock positions has been found to be satisfactory. EN ISO 13478:2007 (E)7Dimensions in millimetres Key lttest 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
44、piston 7 blade 8 end cap Figure 1 Example of test facility for full-scale rapid crack propagation 8.2 Steel-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 ha
45、ve 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 pressurizing the test pipe and steel reservoir (8.2) with the test fluid (7.4) to within 2
46、 % of the test pressure specified by the referring standard. 8.4 Crack-initiation equipment, for driving a metal blade (8.4.2) through the test pipe at high speed. 8.4.1 Router, capable of machining a longitudinal slot to an appropriate depth in the test-pipe wall for approximately 500 mm and then g
47、radually decreasing the groove depth to zero over approximately 250 mm (see Figure 2). NOTE Normally, the slot is machined whilst the test pipe is in the trench. 8.4.2 Metal blade, which can be aligned with the external slot in the test pipe and be driven through the residual pipe-wall thickness. NO
48、TE A 400 mm long steel blade driven by a fast-acting pneumatic impact piston has been found to be suitable for polyethylene pipe (see Figure 3). EN ISO 13478:2007 (E)8Dimensions in millimetres Key w slot width (8 mm to 25 mm, depending on the wall thickness) 1 rounded corners at bottom of slot Figur
49、e 2 Slot machined in external surface of pipe wall Dimensions in millimetres Key 1 part of blade gripped in blade holder NOTE Blade sharpened by light grinding. Figure 3 Steel blade found to be suitable for initiating crack in polyethylene pipe 8.4.3 Crack initiation cooling system, used to apply methylated spirits or ethanol, cooled by solid carbon dioxide, to the top of the pipe in order to cool the slot and a strip of pipe on either side and approximately 1 m in the direction of the steel-pipe reservoir. It is recommend
