1、 Reference number ISO 20703:2006(E) ISO 2006INTERNATIONAL STANDARD ISO 20703 First edition 2006-05-01 Gas cylinders Refillable welded aluminium-alloy cylinders Design, construction and testing Bouteilles gaz Bouteilles rechargeables soudes en alliage daluminium Conception, construction et essais ISO
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5、n below. ISO 2006 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 microfilm, without permission in writing from either ISO at the address below or ISOs member
6、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 2006 All rights reservedISO 20703:2006(E) ISO 2006 All rights reserved iii Contents Page F
7、oreword. v Introduction . vi 1 Scope . 1 2 Normative references . 1 3 Terms, definitions and symbols 2 3.1 Terms and definitions. 2 3.2 Symbols . 2 4 Materials 4 4.1 General provisions . 4 4.2 Heat treatment. 4 4.3 Gas/material compatibility . 5 5 Design 5 5.1 General provisions . 5 5.2 Calculation
8、of wall thickness. 7 5.3 Design of convex ends (heads and bases) 8 5.4 Neck design. 12 5.5 Foot-rings 12 5.6 Neck-rings . 12 5.7 Shroud . 12 5.8 Design drawing . 12 6 Construction and workmanship 12 6.1 Seamless bodies. 12 6.2 Welding 12 6.3 Non-destructive examination of welds. 13 6.4 Surface defec
9、ts . 13 6.5 Neck threads . 13 6.6 Out-of-roundness 14 6.7 Straightness 14 6.8 Eccentricity 14 6.9 Stability 14 7 Tests and examinations . 14 7.1 General. 14 7.2 Mechanical tests . 14 7.3 Hydraulic burst test 21 7.4 Pressure-cycling test 23 7.5 Hydraulic test 24 7.6 Check on the homogeneity of a batc
10、h 24 7.7 Leakage test 24 7.8 Capacity check 24 7.9 Examination for neck folds 24 8 Conformity evaluation 25 9 Identification marks 25 10 Records 25 Annex A (normative) Corrosion tests 26 Annex B (normative) New design type testing and production testing . 40 ISO 20703:2006(E) iv ISO 2006 All rights
11、reservedAnnex C (normative) Description, evaluation of manufacturing defects and conditions for rejection of welded aluminium-alloy gas cylinders at time of visual inspection . 44 Annex D (informative) Examples of new design type approval and production test certificates 48 Bibliography . 54 ISO 207
12、03:2006(E) ISO 2006 All rights reserved v Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member
13、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 part in the work. ISO collaborates closely with the International Electr
14、otechnical 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 to prepare International Standards. Draft International Standards adopted
15、 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 that some of the elements of this document may be the subject of patent
16、rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 20703 was prepared by Technical Committee ISO/TC 58, Gas cylinders, Subcommittee SC 3, Cylinder design. This International Standard has been prepared to address the general requirements in Section 6.2.1 of t
17、he UN model regulations for the transportation of dangerous goods ST/SG/AC.10/1/Rev.13. It is intended to be used under a variety of regulatory regimes but has been written so that it is suitable for use with the conformity assessment system in paragraph 6.2.2.5 of the above mentioned model regulati
18、ons. ISO 20703:2006(E) vi ISO 2006 All rights reservedIntroduction The purpose of this International Standard is to provide a specification for the design, manufacture, inspection and approval of refillable, transportable, welded aluminium-alloy gas cylinders. The specifications given are based on k
19、nowledge of, and experience with, materials, design requirements, manufacturing processes and control during manufacture of cylinders in common use in the countries of the participating members. INTERNATIONAL STANDARD ISO 20703:2006(E) ISO 2006 All rights reserved 1 Gas cylinders Refillable welded a
20、luminium-alloy cylinders Design, construction and testing 1 Scope This International Standard specifies minimum requirements for the material, design, construction and workmanship, manufacturing processes and tests at manufacture of refillable, transportable, welded aluminium-alloy gas cylinders of
21、water capacities from 0,5 l up to and including 150 l, and of a test pressure not greater than 60 bar (6 MPa) for compressed, liquefied and dissolved gases. This International Standard includes requirements for spherical receptacles and cylinders made from seamless bodies with welded non-pressure-be
22、aring attachments such as shrouds and foot-rings. 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 a
23、ny amendments) applies. ISO 2107, Aluminium and aluminium alloys Wrought products Temper designations ISO 6506-1, Metallic materials Brinell hardness test Part 1: Test method ISO 6892, Metallic materials Tensile testing at ambient temperature ISO 7438, Metallic materials Bend test ISO 7866:1999, Gas
24、 cylinders Refillable seamless aluminium alloy gas cylinders Design, construction and testing ISO 9606-2, Qualification test of welders Fusion welding Part 2: Aluminium and aluminium alloys ISO 10042:2005, Welding Arc-welded joints in aluminium and its alloys Quality levels for imperfections ISO 111
25、14-1, Transportable gas cylinders Compatibility of cylinder and valve materials with gas contents Part 1: Metallic materials ISO 11117, Gas cylinders Valve protection caps and valve guards for industrial and medical gas cylinders Design, construction and tests ISO 13341, Transportable gas cylinders
26、Fitting of valves to gas cylinders ISO 13769, Gas cylinders Stamp marking ISO 15614-2:2005, Specification and qualification of welding procedures for metallic materials Welding procedure test Part 2: Arc welding of aluminium and its alloys ISO 20703:2006(E) 2 ISO 2006 All rights reserved3 Terms, def
27、initions and symbols 3.1 Terms and definitions For the purposes of this document the following terms and definitions apply. 3.1.1 yield stress value corresponding to the 0,2 % proof stress (non proportional elongation), R p0,23.1.2 solution heat treatment thermal treatment which consists of heating
28、the products to a suitable temperature, holding at that temperature long enough to allow constituents to enter into solid solution, and cooling rapidly enough to hold the constituents in solution 3.1.3 quenching controlled rapid cooling in a suitable medium to retain the solute phase in solid soluti
29、on 3.1.4 artificial ageing heat treatment process in which the solute phase is precipitated to give an increased yield stress and tensile strength 3.1.5 batch quantity of up to 250 cylinders, plus cylinders for destructive testing, of the same nominal diameter, thickness and design, made successivel
30、y from the same cast and subjected to the same heat treatment for the same period of time; the lengths of the cylinders in the heat treatment batch may vary by up to 12 % 3.1.6 design stress factor F ratio of equivalent wall stress at test pressure (p h ) to guaranteed minimum yield stress (R e ) 3.
31、1.7 non-destructive examination examination or test that does not materially or adversely affect the item being examined 3.2 Symbols A percentage elongation, determined by the tensile test 7.2.3 a calculated minimum thickness, in millimetres, of the cylindrical or spherical shell a guaranteed minimu
32、m thickness, in millimetres, of the cylindrical or spherical shell b guaranteed minimum thickness, in millimetres, at the centre of a convex base D onominal outside diameter, in millimetres, of the cylinder, spherical cylinder or domed end (see Figure 2) D inominal inside diameter, in millimetres, o
33、f the cylinder, spherical cylinder or domed end (see Figure 2) d diameter of former, in millimetres (see Figure 4) F design stress factor (variable) (see 3.1.6) ISO 20703:2006(E) ISO 2006 All rights reserved 3 h iinternal height, in millimetres, of semi-ellipsoidal or torispherical domed end (convex
34、 head or base end) (see Figure 2) h evariable used in the determination of shape factor, K (see 5.3.1) h oexternal height, in millimetres, of a semi-ellipsoidal or torispherical domed end (convex head or base end) (see Figure 2) K shape factor for a semi-ellipsoidal or torispherical domed end, obtai
35、ned according to the values h e /D oand a/D o , with interpolation where necessary (see Figure 1) L ooriginal gauge length, in millimetres, according to ISO 6892 n ratio of the diameter of the bend test former to actual thickness of test piece (t) p bmeasured burst pressure, in bar 1)above atmospher
36、ic pressure p hhydraulic test pressure, in bar 1)above atmospheric pressure p lclower cyclic pressure, in bar 1)above atmospheric pressure p yobserved yield pressure which produces a permanent volumetric expansion of 0,2 %, in bar 1)above atmospheric pressure R eminimum guaranteed value of yield str
37、ess (see 3.1.1), in megapascals, for the finished cylinder R eaactual value of yield stress, in megapascals, determined by the tensile test 7.2.3. R gminimum guaranteed value of tensile strength, in megapascals, for the finished cylinder R mactual value of tensile strength, in megapascals, determine
38、d by the tensile test 7.2.3 r iinternal knuckle radius, in millimetres, of torispherical end see Figure 2c) r i internal radius, in millimetres, of dishing of torispherical end see Figure 2c) r aexternal knuckle radius, in millimetres, of torispherical end see Figure 2c) r o external radius, in mill
39、imetres, of dishing of torispherical end see Figure 2c) s fstraight flange length, in millimetres, for semi-ellipsoidal and torispherical domed ends see Figure 2b) and 2c) S ooriginal cross-sectional area of tensile test piece, in square millimetres, according to ISO 6892 t actual thickness of test
40、specimen, in millimetres t ecalculated minimum thickness, in millimetres, of a domed end w width, in millimetres, of tensile test piece V expvolumetric expansion attained at burst, expressed as a percentage of the initial volume (see 7.3) Z stress reduction factor (see 5.2.1) 1) 1 bar = 10 5Pa = 10
41、5N/m 2 . ISO 20703:2006(E) 4 ISO 2006 All rights reserved4 Materials 4.1 General provisions 4.1.1 Aluminium alloys may be used to produce gas cylinders provided that they satisfy the requirements of the corrosion resistance tests defined in Annex A, and meet all other requirements of this Internatio
42、nal Standard. 4.1.2 Examples of the alloys most commonly used for the fabrication of gas cylinders are given in Table 1. 4.1.3 After the completion of all welding (including that of the attachments) and before the hydraulic test, each cylinder shall be heat treated if required to meet the design cri
43、teria. 4.2 Heat treatment 4.2.1 General Any welding on the pressure-bearing part shall take place before any final heat treatment (see 6.2). 4.2.2 Heat-treatable alloys The manufacturer shall specify on the new design type testing documentation, where required, the solution heat treatment and artifi
44、cial ageing temperatures and the times for which the cylinders have been held at those temperatures. The medium used for quenching after solution heat treatment shall be identified. Unless the alloy is subjected to a temperature in excess of 400 C during the forming process, a stabilizing treatment
45、shall be carried out and the temperature, and time at temperature, shall be identified by the manufacturer. However, the stabilizing treatment is not necessary for a cylinder of which the wall thickness in 5.2 is calculated with the minimum guaranteed yield stress value of the O-tempered alloy (or t
46、he alloy annealed for complete re-crystallization before forming of cylinder, as defined in ISO 2107). If the cylinder is intended for dissolved-gas service it shall only be used in the fully annealed condition, i.e. the minimum guaranteed properties used for the material shall consider the heat tre
47、atment to be applied, e.g. during the massing operation. 4.2.3 Non-heat-treatable alloys The manufacturer shall specify on the new design type testing documentation, where required, the type of metal forming operation carried out (extrusion, drawing, ironing, head forming, etc.). Unless the alloy is
48、 subjected to a temperature in excess of 400 C during the forming process, a stabilizing treatment shall be carried out and the temperature, and time at temperature, shall be identified by the manufacturer. 4.2.4 Control of specified heat treatment During the heat treatment, the manufacturer shall c
49、omply with the specified temperatures and durations, within the following ranges: a) Temperatures Solution temperature: maximum range 20 C Artificial ageing temperature: maximum range 20 C Stabilizing temperature: maximum range 20 C ISO 20703:2006(E) ISO 2006 All rights reserved 5 b) Durations Time cylinders actually spend at temperature during treatments: All treatments: maximum range 20 % 4.3 Gas/material compatibility Gas/material compatibility shall be verified as
