1、BSI Standards PublicationBS ISO 18851:2015Plastics piping systems Glass-reinforced thermosettingplastics (GRP) pipes and fittings Test method to prove thestructural design of fittingsBS ISO 18851:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 18851:2015.T
2、he UK participation in its preparation was entrusted to TechnicalCommittee PRI/88/2, Plastics piping for pressure applications.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of
3、a contract. Users are responsible for its correctapplication. The British Standards Institution 2015. Published by BSI Standards Limited 2015ISBN 978 0 580 83274 1ICS 23.040.20Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under th
4、e authority of theStandards Policy and Strategy Committee on 31 March 2015.Amendments/corrigenda issued since publicationDate Text affectedBS ISO 18851:2015 ISO 2015Plastics piping systems Glass-reinforced thermosetting plastics (GRP) pipes and fittings Test method to prove the structural design of
5、fittingsSystmes de canalisation en matires plastiques Tubes et raccords plastiques thermodurcissables renforcs de verre (PRV) Mthode dessai pour prouver la conception structurelle des raccordsINTERNATIONAL STANDARDISO18851First edition2015-03-15Reference numberISO 18851:2015(E)BS ISO 18851:2015ISO 1
6、8851:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the intern
7、et or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso
8、.orgPublished in SwitzerlandBS ISO 18851:2015ISO 18851:2015(E)Foreword iv1 Scope . 12 Terms and definitions . 13 Principle 14 Apparatus . 24.1 End sealing devices . 24.1.1 General 24.1.2 Capable of applying the end loads 24.1.3 Not capable of applying the end loads 24.2 Supports 24.2.1 End thrust su
9、pports 24.2.2 Straps and Cradles 24.3 Source of hydrostatic pressure . 24.4 Means to measure the gauge pressure . 25 Test pieces . 25.1 Test arrangement 25.2 Number of test pieces . 36 Conditioning 47 Test temperature 48 Procedure. 48.1 Tests to be performed . 48.2 Test Failure Criteria 48.2.1 Burst
10、ing . 48.2.2 Leaking . 48.2.3 Weeping . 48.3 Initial leakage . 48.4 Resistance to internal pressure 59 Test report . 5Bibliography 7 ISO 2015 All rights reserved iiiContents PageBS ISO 18851:2015ISO 18851:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federati
11、on of national 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
12、. International 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.The procedures used to develop this document and tho
13、se intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (
14、see www.iso.org/directives). 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. Details of any patent rights identified during the development of the do
15、cument will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms a
16、nd expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 138, Plastics pipes, fittings a
17、nd valves for the transport of fluids, Subcommittee SC 6, Reinforced plastics pipes and fittings for all applications.iv ISO 2015 All rights reservedBS ISO 18851:2015Plastics piping systems Glass-reinforced thermosetting plastics (GRP) pipes and fittings Test method to prove the structural design of
18、 fittings1 ScopeThis International Standard specifies methods of test for fittings of any form, i.e. bends, branches, tapers, intended to be used in plastics piping systems for pressure and non-pressure drainage and sewerage or water supply made of glass-reinforced thermosetting plastics (GRP). This
19、 International Standard is applicable to fittings, in order to test their structural design, but is not applicable to connecting joint systems. It assumes that the fitting either is or is not intended to be subject to the effects of hydrostatic end thrust.The tests detailed in 8.1 to 8.4 are applica
20、ble to fittings intended to be used in buried or non-buried applications.These test procedures are applicable to fittings of all nominal sizes specified in the referring standard. The tests are for evaluating fittings intended for use in applications conveying liquids at temperatures specified in th
21、e referring standards.The test procedures in this International Standard are damaging to the test piece which will not be suitable for reuse after these tests. The test procedure is applicable to type testing.NOTE This International Standard is not intended to be used for the assessment of the perfo
22、rmance of non-integrated joints as there are already international test methods for this purpose. See Bibliography.2 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.2.1pressurehydrostatic gauge pressure3 PrincipleA fitting is subjected to a specified
23、 internal pressure with or without end thrust. The procedure includes prolonged static tests at elevated pressures.At the end of each of the tests, the test piece is inspected for signs of failure as defined in 8.2.It is assumed that the following test parameters are set by the standard making refer
24、ence to this International Standard:a) number of test pieces to be used (see 5.2);b) if applicable, conditioning other than given in Clause 6;c) test temperature and its permissible deviations (see Clause 7);d) nominal pressure relevant to the fitting under test (see 5.1 and Clause 8);e) if applicab
25、le, any criteria indicative of structural damage to the fitting see Clause 8 and Clause 9 i);f) whether the fitting is or is not to be tested with end loads.INTERNATIONAL STANDARD ISO 18851:2015(E) ISO 2015 All rights reserved 1BS ISO 18851:2015ISO 18851:2015(E)4 Apparatus4.1 End sealing devices4.1.
26、1 GeneralEnd sealing devices shall be of a size and type appropriate to the fitting under test.4.1.2 Capable of applying the end loadsIf the fitting is to be tested with the end load see Clause 3 f), then the end sealing devices shall be anchored to transfer internal pressure end thrust to the fitti
27、ng.4.1.3 Not capable of applying the end loadsIf the fitting is to be tested without the end load see Clause 3 f), then the end-sealing devices shall not be anchored to the fitting. Typically, the end caps for such applications rely on tie-rod(s) through the bore of the test piece or on an external
28、structure to resist internal pressure end thrust.4.2 Supports4.2.1 End thrust supportsIf required, the end thrust supports shall comprise part of the test rig and shall be capable of supporting the end thrust induced by the internal pressure but shall not otherwise support the fitting. Non-end thrus
29、t loaded fittings can be tested using appropriately designed reinforced concrete encasements. For branches, the branch pipe shall be designed to resist end-loading due to end thrust. The header pipe can be tested either with or without the end-load thrust.NOTE If concrete encasements are used, their
30、 design and reinforcement are to be described in detail to ensure that the design of the thrust supports represents the actual conditions on site.4.2.2 Straps and CradlesIf used, straps or cradles for use as supports shall be of sufficient width for the fitting components of the test piece and shall
31、 not have a detrimental effect on the test piece, e.g. shall not apply point loads.4.3 Source of hydrostatic pressureA source of hydrostatic pressure to meet the needs of the test.4.4 Means to measure the gauge pressureA means to measure the gauge pressure which has a calibrated accuracy within 1 %
32、at the specified gauge pressure (see 8.3 and 8.4.)5 Test pieces5.1 Test arrangementThe test piece shall comprise a fitting of the correct size and pressure class, including appropriate end sealing devices.For the tests detailed in 8.3 and 8.4, the arrangement shall be as shown in Figure 1.2 ISO 2015
33、 All rights reservedBS ISO 18851:2015ISO 18851:2015(E)The test piece shall be assembled in accordance with the manufacturers recommendations and the requirements of the referring standard.5.2 Number of test piecesUnless otherwise specified, the number of test pieces shall be one.a) Arrangement with
34、end loadsb) Arrangement without end loadsKey1 thrust carried by test piece2 end sealing device3 thrust carried by test rig4 fitting being testedFigure 1 Typical test arrangement for a branch for the tests detailed in 8.3 and 8.4NOTE Figure 1 shows test arrangements for a branch. Any other type of fi
35、tting can be tested using the procedures mentioned in this International Standard. ISO 2015 All rights reserved 3BS ISO 18851:2015ISO 18851:2015(E)6 ConditioningUnless otherwise specified in the referring standard, following assembly and filling, the filled test piece shall be conditioned by storing
36、 at the test temperature (see Clause 7) for at least 24 h prior to testing until the required temperature is reached (medium and test sample).NOTE Conditioning time is a function of pipe specimen wall thickness, water volume, temperature differential, the film heat transfer coefficient, and whether
37、the elevated temperature environment is applied to one or both sides of the specimen.7 Test temperatureConduct the following procedure in Clause 8 at the temperature specified in the referring standard.8 Procedure8.1 Tests to be performedSubject the test piece (see Clause 4) to the tests in 8.3 and
38、8.4 and summarized in Table 1. Fittings intended to carry end thrust shall be tested in this condition. Fittings not intended to carry end thrust shall be tested with the end sealing devices not restrained to the fitting but with the end load carried by independent supports. The pressure gauge shall
39、 measure the hydrostatic pressure applied at the top of the fitting.NOTE Each reference to hydrostatic pressure specifies a positive internal pressure, relative to atmospheric pressure, expressed as multiples of the nominal pressure (PN) that is relevant to the fitting under test.If a test is interr
40、upted, record the details in the test report and resume after reconditioning (until the required temperature is reached of the medium and test sample). Failure of the testing apparatus (see Clause 4) shall not constitute failure of the test piece, but if the test conditions are invalidated thereby,
41、continue the particular test after replacing the failed component.8.2 Test Failure CriteriaFailure is the occurrence of bursting, leaking, or weeping.8.2.1 BurstingFailure by rupture of the test sample resulting in the immediate loss of test liquid and drop of pressure.8.2.2 LeakingVisible failure b
42、y loss of the pressurising liquid through the test sample.8.2.3 WeepingFailure by loss of the pressurising liquid through the test sample to an extent detectable visually.NOTE For tests performed at elevated temperature in enclosed conditioning rooms, visual detection might not be practical. Therefo
43、re, alternative methods might be used to detect weeping such as electronic detection, colouring of the test liquid, etc.8.3 Initial leakage8.3.1 Fill the test piece with water and vent to remove any air.4 ISO 2015 All rights reservedBS ISO 18851:2015ISO 18851:2015(E)8.3.2 Apply the internal pressure
44、 of 1,5 times the nominal pressure of the fitting, expressed in bar1)and maintain it above or equal to that pressure for 15 min (see Table 1).8.3.3 Inspect the fitting for signs of leakage. If leakage is not present, proceed. Otherwise, stop the test and record the observations.8.4 Resistance to int
45、ernal pressure8.4.1 Perform following procedure:Steadily increase the pressure to 2,5 times the nominal pressure of the fitting, expressed in bars, and maintain it above or equal to that pressure for 100 h (see Table 1). During this procedure, the fitting shall not show any kind of failure described
46、 in 8.2.8.4.2 Reduce the pressure to atmospheric and empty the test piece.8.4.3 Inspect the test piece and record any signs of failure of the fitting.Table 1 Summary of test requirementsProperty to be testedTest to be performed Test pressure Duration Clause numberInitial leakage initial pressure 1,5
47、 times PN 15 min 8.3 and Figure 1Resistance to internal pressuremaintained pressure 2,5 times PN 100 h8.4 and Figure 1NOTE Nominal pressure (PN) is an alphanumeric designation of pressure related to the resistance of a compo-nent of a piping system to internal pressure.9 Test reportThe test report s
48、hall include the following information:a) a reference to this International Standard, i.e. ISO 18851:2014, and to the referring standard;b) whether the fitting was tested with or without end thrust;c) full identification of the fitting tested;d) nominal pressure class (PN) of the fitting;e) temperat
49、ure range during the test;f) using clause numbers in this International Standard describe the tests to which the fitting was subjected;g) internal pressures, in bars, and test duration;h) any observations of the failure of the fitting during each test;i) any observations on the condition of the fitting during and after each test;j) the details of interruptions, if any, to the test sequence;k) any factors which might have influenced the results, such as any incidents or any operating details not specified in this International Stand
