1、 Reference number ISO 6993-1:2006(E) ISO 2006INTERNATIONAL STANDARD ISO 6993-1 First edition 2006-06-01 Buried, high-impact poly(vinyl chloride) (PVC-HI) piping systems for the supply of gaseous fuels Part 1: Pipes for a maximum operating pressure of 1 bar (100 kPa) Systmes de canalisations enterres
2、 en poly(chlorure de vinyle) rsistance au choc amliore (PVC-HI) pour rseaux de combustibles gazeux Partie 1: Tubes pour une pression maximale de service de 1 bar (100 kPa) ISO 6993-1:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this
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5、 that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2006 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
6、 in any form or by any means, electronic or mechanical, including photocopying 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 office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41
7、 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2006 All rights reservedISO 6993-1:2006(E) ISO 2006 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Symbols and abbreviated terms . 4 5 Material
8、 5 6 General characteristics 6 7 Geometrical characteristics. 6 8 Physical characteristics. 8 9 Mechanical characteristics 8 10 General requirements for pipes 9 11 Test methods. 10 12 Marking 11 Annex A (normative) Determination of resistance to gas constituents . 12 Annex B (normative) Determinatio
9、n of resistance of pipes to external blows 16 Bibliography . 17 ISO 6993-1:2006(E) iv ISO 2006 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standard
10、s 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 take
11、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 t
12、o 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
13、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 6993-1 was prepared by Technical Committee ISO/TC 138, Plastics pipes, fittings and valves for the transport of fluids, Subcommittee SC
14、 4, Plastics pipes and fittings for the supply of gaseous fuels. This first edition of ISO 6993-1, together with ISO 6993-2, ISO 6993-3 and ISO 6993-4, cancels and replaces ISO 6993:2001, of which it constitutes a technical revision. ISO 6993 consists of the following parts, under the general title
15、Buried, high-impact poly(vinyl chloride) (PVC-HI) piping systems for the supply of gaseous fuels: Part 1: Pipes for a maximum operating pressure of 1 bar (100 kPa) Part 2: Fittings for a maximum operating pressure of 200 mbar (20 kPa) Part 3: Fittings and saddles for a maximum operating pressure of
16、1 bar (100 kPa) Part 4: Code of practice for design, handling and installation INTERNATIONAL STANDARD ISO 6993-1:2006(E) ISO 2006 All rights reserved 1 Buried, high-impact poly(vinyl chloride) (PVC-HI) piping systems for the supply of gaseous fuels Part 1: Pipes for a maximum operating pressure of 1
17、 bar (100 kPa) 1 Scope This part of ISO 6993 specifies the requirements for pipes made of high-impact poly(vinyl chloride) (PVC-HI) intended to be used for the supply of gaseous fuels through buried pipelines having an operating temperature range of 0 C up to and including +30 C and a maximum operat
18、ing pressure of 1 bar (100 kPa)1) . It is applicable only to pipes manufactured from the high-impact PVC materials PVC-A, PVC-CPE and PVC-EPR. The pipes are suitable for those gases not containing potentially damaging components in such concentrations as to impair the properties of the pipe material
19、. 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 of the referenced document (including any amendments) applies. ISO 1167-1:2006, Thermop
20、lastics pipes, fittings and assemblies for the conveyance of fluids Determination of the resistance to internal pressure Part 1: General method ISO 2505:2005, Thermoplastics pipes Longitudinal reversion Test method and parameters ISO 2507-1, Thermoplastics pipes and fittings Vicat softening temperat
21、ure Part 1: General test method ISO 2507-2, Thermoplastics pipes and fittings Vicat softening temperature Part 2: Test conditions for unplasticized poly(vinyl chloride) (PVC-U) or chlorinated poly(vinyl chloride) (PVC-C) pipes and fittings and for high impact resistance poly(vinyl chloride) (PVC-HI)
22、 pipes ISO 3126, Plastics piping systems Plastics components Determination of dimensions ISO 3127, Thermoplastics pipes Determination of resistance to external blows Round-the-clock method ISO 9080, Plastics piping and ducting systems Determination of the long-term hydrostatic strength of thermoplas
23、tics materials in pipe form by extrapolation ISO 9852, Unplasticized poly(vinyl chloride) (PVC-U) pipes Dichloromethane resistance at specified temperature (DCMT) Test method ISO 9969, Thermoplastics pipes Determination of ring stiffness 1) 1 bar = 0,1 MPa = 10 5 Pa; 1 MPa = 1 N/mm 2ISO 6993-1:2006(
24、E) 2 ISO 2006 All rights reservedISO 16871, Plastics piping and ducting systems Plastics pipes and fittings Method for exposure to direct (natural) weathering EN 922:1994, Plastics piping and ducting systems Pipes and fittings of unplasticized poly(vinyl chloride) (PVC-U) Specimen preparation for de
25、termination of the viscosity number and calculation of the K-value 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 Geometrical definitions 3.1.1 nominal outside diameter d nnumerical designation of size which is common to all components in a
26、thermoplastics piping system other than flanges and components designated by thread size NOTE 1 It is a convenient round number for reference purposes. NOTE 2 For metric pipes conforming to ISO 161-1, the nominal outside diameter, expressed in millimetres, is the minimum mean outside diameter d em,
27、min . 3.1.2 mean outside diameter d emmeasured length of the outer circumference of the pipe divided by , rounded up to the nearest 0,1 mm NOTE The value for is taken to be 3,142. 3.1.3 minimum outside diameter d e,minminimum value of the mean outside diameter NOTE It is equal to the nominal outside
28、 diameter d n , expressed in millimetres. 3.1.4 maximum outside diameter d e,maxmaximum value of the mean outside diameter 3.1.5 outside diameter at any point d emeasured outside diameter through the cross-section at any point of the pipe, rounded up to the nearest 0,1 mm 3.1.6 out-of-roundness diff
29、erence between the measured maximum outside diameter and the measured minimum outside diameter in the same cross-sectional plane of the pipe 3.1.7 nominal wall thickness e nwall thickness, in millimetres, tabulated in ISO 4065, corresponding to the minimum wall thickness, e min , at any point ISO 69
30、93-1:2006(E) ISO 2006 All rights reserved 3 3.1.8 mean wall thickness e marithmetic mean of at least four measurements regularly spaced around the same cross-sectional plane of the pipe, including the measured minimum and maximum values obtained, rounded up to the nearest 0,1 mm 3.1.9 wall thickness
31、 at any point e measured wall thickness at any point around the circumference of the pipe, rounded up to the nearest 0,1 mm. 3.1.10 standard dimension ratio SDR numerical designation of a pipe series, which is approximately equal to the ratio of the nominal outside diameter d nto the nominal wall th
32、ickness e n : n n SDR d e = NOTE It is a convenient round number for reference purposes. 3.2 Material definitions 3.2.1 high-impact poly(vinyl chloride) PVC-HI mixture of unplasticized PVC and an impact-resistance modifier 3.2.2 lower confidence limit of the predicted hydrostatic strength LPLquantit
33、y with the dimensions of stress, which represents the 97,5 % lower confidence limit of the predicted hydrostatic strength for a single value at a temperature T and a time t NOTE It is denoted as LPL= (T, t, 0,975) . 3.2.3 minimum required strength MRS value of LPL , at a temperature of 20 C and a ti
34、me 50 years, (20, 50 years, 0,975) , rounded down to the next smaller value of the R 10 series or of the R 20 series conforming to ISO 3 and ISO 497, depending on the value of LPL3.2.4 overall service design coefficient C overall coefficient with a value greater than 1, which takes into consideratio
35、n service conditions as well as properties of the components of a piping system other than those represented in the LPL3.3 Definitions related to service conditions 3.3.1 natural gas gaseous fuel containing a mixture of hydrocarbons, primarily methane, but generally also including ethane, propane an
36、d higher hydrocarbons in much smaller amounts, as well as some inert gases such as nitrogen and carbon dioxide, plus minor amounts of trace constituents NOTE Natural gas remains in the gaseous state under the temperature and pressure conditions normally found in service. ISO 6993-1:2006(E) 4 ISO 200
37、6 All rights reserved3.3.2 pressure overpressure relative to atmospheric pressure 3.3.3 maximum operating pressure MOP maximum effective pressure of the gas in a piping system, expressed in bars, which is allowed in continuous use NOTE 1 It takes into account the physical and the mechanical characte
38、ristics of the components of the piping system. NOTE 2 MOP is given by the equation: 20 MRS MOP (SDR 1) C = 4 Symbols and abbreviated terms 4.1 Symbols C overall service (design) coefficient d e outside diameter at any point d e,max maximum outside diameter d em mean outside diameter d e,min minimum
39、 outside diameter d nnominal outside diameter e n nominal wall thickness ewall thickness at any point e max maximum wall thickness e m mean wall thickness e min minimum wall thickness hoop stress LPL lower confidence limit ISO 6993-1:2006(E) ISO 2006 All rights reserved 5 4.2 Abbreviated terms PVC-A
40、 acrylate modified PVC PVC-CPE chlorinated polyethylene modified PVC PVC-EPR ethylene propylene rubber modified PVC MOP maximum operating pressure MRS minimum required strength PVC-HI high-impact PVC PVC-U unplasticized PVC SDR standard dimension ratio STIS specific tangential initial stiffness THT
41、tetrahydrothiophene 5 Material 5.1 Composition The pipes shall be made of high-impact PVC, to which only such additives are added that are necessary to facilitate conformity of the components to this part of ISO 6993. The impact-resistant modified PVC shall be one of the following compositions: a) a
42、 mixture based on PVC; b) a blend based on PVC; c) a copolymer based on PVC; d) a combination of these types. The proportion of the impact modifier in the composition shall be at least 7 % by mass. 5.2 Long-term strength The MRS value of the extrusion material shall be at least 18 MPa. Conformity to
43、 this requirement shall be proven using a long-term evaluation in accordance with ISO 9080. Testing shall be carried out at 20 C, 40 C and 60 C, for periods up to 9 000 h. At 60 C no knee shall occur before 5 000 h. This test shall be carried out on test pieces in the form of a solid wall extruded p
44、ipe made from the relevant extrusion material. NOTE The MRS evaluation is used for a material qualification and is not intended to be used for a pressure rating. 5.3 Vicat softening temperature The Vicat softening temperature of the extrusion material shall be not less than 76 C when determined in a
45、ccordance with ISO 2507-1 and ISO 2507-2. ISO 6993-1:2006(E) 6 ISO 2006 All rights reserved5.4 K-value The K-value of the unplasticized polyvinyl chloride (PVC-U) resin in the extrusion material shall exceed 65, when measured in accordance with EN 922. 5.5 UV stability Test samples of the extrusion
46、material in the form of a pipe of d n63 shall be exposed to weathering in accordance with 11.1 and 11.3. After exposure, the impact resistance of the weathered side shall be determined in accordance with Annex B, using a falling weight of (750 5 0 ) + g and a drop height of (2 000 10 0 + ) mm at 0 C
47、. 5.6 Resistance to gas constituents The resistance to gas constituents shall be determined in accordance with 11.1 and Annex A. 6 General characteristics 6.1 Contaminants The material of the pipe shall not be shown to contain any contaminants, such as inorganic particles or agglomerations thereof,
48、exceeding 50 m in size, when measured in accordance with 11.1 and 11.2. 6.2 Appearance and finish The appearance and finish of the pipes shall be examined visually without magnification. Internal and external pipe surfaces shall be free from grooves, pits, blisters, indications of burning and other
49、irregularities. The pipe ends shall be cut cleanly and square to the axis of the pipe. The cut end shall not show any voids. 7 Geometrical characteristics 7.1 Measurements All dimensions shall be measured in accordance with ISO 3126. 7.2 Nominal outside diameter The nominal outside diameter, d n , shall be selected from those given in Table 1. 7.3 Mean outside diameter The mean outside diameter at any point, d em , shall be in accordance with Table
