1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 18225:2012Plastics piping systems Multilayer piping systems foroutdoor gas installations Specifications for systemsBS ISO 18225:2012 BRITISH STANDARDNational forewordThis
2、British Standard is the UK implementation of ISO 18225:2012. Itsupersedes BS ISO 18225:2007 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/88/2, Plastics piping for pressure applications.A list of organizations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 beo
3、btained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 77614 4ICS 23.040.20; 23.040.45;
4、75.200Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate Text affectedBS ISO 18225:2012 ISO 2012Plastics pipi
5、ng systems Multilayer piping systems for outdoor gas installations Specifications for systemsSystmes de canalisations en plastique Tubes multicouches destins lalimentation en gaz lextrieur des btiments Spcifications pour les systmesINTERNATIONAL STANDARDISO18225Second edition2012-12-01Reference numb
6、erISO 18225:2012(E)BS ISO 18225:2012ISO 18225:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All 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 photoco
7、pying and microfilm, without permission in writing 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.orgPublished in SwitzerlandBS
8、 ISO 18225:2012ISO 18225:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 23.1 Structural definitions 23.2 Geometrical definitions . 33.3 Definitions related to pressure . 43.4 Materials definitions 43.5 Defini
9、tions related to material characteristics 43.6 Terms related to service conditions . 54 Pipes 54.1 Material . 54.2 General characteristics . 64.3 Dimensions of pipes . 64.4 Mechanical properties 84.5 Physical properties . 105 Fittings .115.1 Fittings reference standards 115.2 Materials 115.3 Dimensi
10、ons 115.4 Elastomeric seals 116 Fitness for purpose of the system 117 Marking and documentation 127.1 Legibility 127.2 Damage . 127.3 Minimum marking requirements 12Annex A (normative) List of reference product standards .14Annex B (normative) Testing resistance to gas constituents .15Annex C (norma
11、tive) Testing resistance to weathering of outer layer of M-pipes .16Bibliography .17BS ISO 18225:2012ISO 18225:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Stand
12、ards 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. International organizations, governmental and non-governmental, in liaison with ISO, also ta
13、ke 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 rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is
14、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 at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility
15、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 18225 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids, Subcommittee SC 4
16、, Plastics pipes and fittings for the supply of gaseous fuels.This second edition cancels and replaces the first edition (ISO 18225:2007) which has been technically revised.iv ISO 2012 All rights reservedBS ISO 18225:2012ISO 18225:2012(E)IntroductionThe test methods used in this International Standa
17、rd have been developed by ISO TC 138/SC 5 as far as possible. However, not all the required methods were in the SC 5 standards development work programme at the time of publication of this International Standard, so they have been placed in its annexes. When those methods are developed for other Int
18、ernational Standards, these annexes will be redundant.For multilayer pipe construction consisting of a layer of a reference standard material, an adhesive and a non-stress-designed layer Procedure I and the relevant product standards are required to be followed for all aspects, excepting for those o
19、f delamination and if applicable oxygen permeation.For example, layers can have the following purposes: the ability to withstand pressure; the ability to realize interlayer adhesion; the ability to block or greatly diminish incoming UV light and/or sunlight; the ability for mechanical protection; th
20、e ability to control longitudinal expansion; the ability to give the multilayer pipe a colour (inside or outside layer).Moreover, some characteristics can be combined in one layer. ISO 2012 All rights reserved vBS ISO 18225:2012BS ISO 18225:2012Plastics piping systems Multilayer piping systems for o
21、utdoor gas installations Specifications for systems1 ScopeThis International Standard specifies general and performance requirements for multilayer pipe systems based on pipes made from thermoplastics and intended to be used for gas supply outdoors.It gives requirements for the design of pipe system
22、s consisting of multilayer pipes based on thermoplastics and for which at least 60 % of the wall thickness is of a polymeric material. The polymeric material used for stress design layers and all inner layers must be polyethylene (PE) and/or crosslinked polyethylene (PE-X), in accordance with Annex
23、A. The outer layers of metal multilayer pipes must be of either PE or PE-X.NOTE For the purposes of this International Standard, PE-RT is considered as PE, while PE-X and adhesive layers are considered as thermoplastics materials.This International Standard is applicable to systems intended to be op
24、erated at temperatures ranging from 20 C to 40 C. It is applicable to pipes in these systems having a nominal diameter up to and including 630 mm, and to the supply of gaseous fuels of categories D (natural gas) and E (LPG vapour and natural gas or LPG vapour) (see ISO 13623).2 Normative referencesT
25、he 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 of the referenced document (including any amendments) applies.ISO 161-1, Thermoplastics pipes for the conveyance
26、of fluids Nominal outside diameters and nominal pressures Part 1: Metric seriesISO 497, Guide to the choice of series of preferred numbers and of series containing more rounded values of preferred numbersISO 1167 (all parts),Thermoplastics pipes, fittings and assemblies for the conveyance of fluids
27、Determination of the resistance to internal pressureISO 3126, Plastics pipes Measurement of dimensionsISO 4437, Buried polyethylene (PE) pipes for the supply of gaseous fuels Metric series SpecificationsISO 6447, Rubber seals Joint rings used for gas supply pipes and fittings Specification for mater
28、ialISO 8085-3, Polyethylene fittings for use with polyethylene pipes for the supply of gaseous fuels Metric series Specifications Part 3: Electrofusion fittingsISO 9080, Plastics piping and ducting systems Determination of the long-term hydrostatic strength of thermoplastics materials in pipe form b
29、y extrapolationISO 9969, Thermoplastics pipes Determination of ring stiffnessISO 10146, Crosslinked polyethylene (PE-X) pipes Effect of time and temperature on the expected strengthISO 10838-1, Mechanical fittings for polyethylene piping systems for the supply of gaseous fuels Part 1: Metal fittings
30、 for pipes of nominal outside diameter less than or equal to 63 mmINTERNATIONAL STANDARD ISO 18225:2012(E) ISO 2012 All rights reserved 1BS ISO 18225:2012ISO 18225:2012(E)ISO 11922-1, Thermoplastics pipes for the conveyance of fluids Dimensions and tolerances Part 1: Metric seriesISO 12162, Thermopl
31、astics materials for pipes and fittings for pressure applications Classification and designation Overall service (design) coefficientISO 13968, Plastics piping and ducting systems Thermoplastics pipes Determination of ring flexibilityISO 14531-1, Plastics pipes and fittings Crosslinked polyethylene
32、(PE-X) pipe systems for the conveyance of gaseous fuels Metric series Specifications Part 1: PipesISO 14531-2, Plastics pipes and fittings Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels Metric series Specifications Part 2: Fittings for heat-fusion jointingISO 14531-
33、3. Plastics pipes and fittings Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels Metric series Specifications Part 3: Fittings for mechanical jointing (including PE-X/metal transitions)ISO 16871, Plastics piping and ducting systems Plastics pipes and fittings Method fo
34、r exposure to direct (natural) weatheringISO 17454, Plastics piping systems Multilayer pipes Test method for the adhesion of the different layers using a pulling rigISO 17456:2006, Plastics piping systems Multilayer pipes Determination of long-term strengthISO 24033, Polyethylene of raised temperatu
35、re resistance (PE-RT) pipes Effect of time and temperature on the expected strengthEN 573-3, Aluminium and aluminium alloys Chemical composition and form of wrought products Part 3: Chemical compositionEN 12117, Plastics piping systems Fittings, valves and ancillaries Determination of gaseous flow r
36、ate/pressure drop relationships3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1 Structural definitions3.1.1multilayer pipepipe comprised of several stress-designed layers3.1.2multilayer M pipemultilayer pipe comprised of polymeric stress-designe
37、d layers and one embedded metallic layer, whose pipe wall thickness consists of at least 60 % of polymeric layers3.1.3multilayer P pipepipe comprised of more than one stress-designed polymeric layerEXAMPLE PE/PE-X.3.1.4layerhomogeneous circumferential section of pipe wall that has chemical and/or me
38、chanical and/or physical characteristics different from those of its immediate neighbours2 ISO 2012 All rights reservedBS ISO 18225:2012ISO 18225:2012(E)3.1.5inner layerlayer in contact with the conveyed fluid3.1.6outer layerlayer exposed to the outer environment3.1.7embedded layerlayer between the
39、outer and inner layer3.1.8stress-designed layerpolymeric layer which is designed to be stress-bearing3.2 Geometrical definitions3.2.1nominal diameterdnspecified diameter, in millimetres, assigned to a nominal size (DN/OD or DN/ID)3.2.2outside diameterdeoutside diameter measured through its cross-sec
40、tion at any point of a pipe, or the fitting end of a fitting, rounded to the next greater 0,1 mm3.2.3mean outside diameterdemmeasured length of the outer circumference of the pipe divided by , rounded up to the nearest 0,1 mmNOTE The value for is taken to be 3,142.3.2.4inside diameterdivalue of the
41、measurement of the inside diameter through its cross-section at any point of a pipe, rounded to the next greater 0,1 mm3.2.5mean inside diameterdimaverage value of a number of equally spaced measurements of inside diameter in the same cross-section of the pipe, rounded to the next greater 0,1 mm3.2.
42、6metal layer standard dimension ratioSDRmnominal outside diameter of the metal layer of the pipe divided by the nominal wall thickness of the metal layer (DN or OD/en,m)3.2.7nominal wall thicknessenwall thickness corresponding to the minimum wall thickness at any point ISO 2012 All rights reserved 3
43、BS ISO 18225:2012ISO 18225:2012(E)3.2.8total wall thicknessemeasured total wall thickness at any point around the circumference of the component, rounded up to the nearest 0,1 mm3.2.9layer wall thicknesselmeasured wall thickness of the layer at any point around the circumference of the component, ro
44、unded up to the nearest 0,01 mm3.2.10minimum layer wall thicknesselminminimum value of the measured wall thickness of a layer at any point around the circumference of the component, rounded up to the nearest 0,01 mm3.3 Definitions related to pressure3.3.1design pressurepDhighest pressure related to
45、the circumstances for which the system has been designed and intended to be used3.4 Materials definitions3.4.1virgin materialmaterial in a form such as granules or powder that has not been subjected to use or processing other than that required for its manufacture and to which no reprocessable or re
46、cyclable material has been added3.4.2own reprocessable materialmaterial prepared from rejected unused pipes and fittings, including trimmings from the production of pipes and fittings that will be reprocessed in a manufacturers plant after having been previously processed by the same manufacturer by
47、 a process such as moulding or extrusion and for which the complete formulation is known3.4.3reference product standardInternational Standard or Draft International Standard prepared by ISO/TC 138/SC 4, applicable for non-multilayer pipes, to which this International Standard can refer for clauses r
48、elated to the materials, components (e.g. fittings), and fitness for purpose of the system3.5 Definitions related to material characteristics3.5.1lower confidence limit of the predicted hydrostatic strengthLPLquantity, with the dimensions of stress, expressed in megapascals (MPa), which represents t
49、he 97,5 % lower confidence limit of the predicted hydrostatic strength for a single value at a temperature, T, and time, t, and which is expressed asLPL(,0,975)=Tt4 ISO 2012 All rights reservedBS ISO 18225:2012ISO 18225:2012(E)3.5.2minimum required strengthMRSvalue of LPLat a temperature 20 C and a time 50 years (20, 50years, 0,975), rounded down to the next smaller value of the R10 series or of the R20 series confor
