1、 Reference number ISO 2928:2003(E) ISO 2003INTERNATIONAL STANDARD ISO 2928 Third edition 2003-08-15 Rubber hoses and hose assemblies for liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas up to 25 bar (2,5 MPa) Specification Tuyaux et flexibles en caoutchouc pour gaz de ptr
2、ole liqufi (GPL) en phase liquide ou gazeuse et le gaz naturel jusqu 25 bar (2,5 MPa) Spcifications ISO 2928:2003(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typeface
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5、vent that a problem relating to it is found, please inform the Central Secretariat at the address given below. ISO 2003 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 photocop
6、ying 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 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzer
7、land ii ISO 2003 All rights reservedISO 2928:2003(E) ISO 2003 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references . 1 3 Terms and definitions. 2 4 Classification. 2 5 Materials and construction 2 6 Dimensions 3 7 Physical properties . 5 8 Electrical resistance . 7 9 Fre
8、quency of testing. 7 10 Marking. 8 Annex A (normative) Flammability test 9 Annex B (normative) Frequency of testing for type approval and routine tests . 11 Annex C (informative) Recommended frequency of testing for production acceptance tests 12 ISO 2928:2003(E) iv ISO 2003 All rights reservedForew
9、ord 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 body interested in a subject for which a techni
10、cal 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 Electrotechnical Commission (IEC) on all matters of e
11、lectrotechnical 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 by the technical committees are circulated to
12、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 rights. ISO shall not be held responsible for i
13、dentifying any or all such patent rights. ISO 2928 was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 1, Hoses (rubber and plastics). This third edition cancels and replaces the second edition (ISO 2928:1986), which has been technically revised. INTERNATIONAL
14、STANDARD ISO 2928:2003(E) ISO 2003 All rights reserved 1Rubber hoses and hose assemblies for liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas up to 25 bar (2,5 MPa) Specification WARNING Persons using this International Standard should be familiar with normal laboratory p
15、ractice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate health and safety practices and to ensure compliance with any national regulatory conditions. 1 Scope This International Stand
16、ard specifies requirements for rubber hoses and rubber hose assemblies used for the transfer of liquefied petroleum gas (LPG) in the liquid or gaseous phase and natural gas and designed for use at working pressures ranging from vacuum to a maximum of 25 bar (2,5 MPa) within the temperature range 30
17、C to +70 C or, for low-temperature hoses (designated -LT), within the temperature range 50 C to +70 C. 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 l
18、atest edition of the referenced document (including any amendments) applies. ISO 37, Rubber, vulcanized or thermoplastic Determination of tensile stress-strain properties ISO 188:1998, Rubber, vulcanized or thermoplastic Accelerated ageing and heat resistance tests ISO 1402, Rubber and plastics hose
19、s and hose assemblies Hydrostatic testing ISO 1746, Rubber or plastics hoses and tubing Bending tests ISO 1817, Rubber, vulcanized Determination of the effect of liquids ISO 4649:2002, Rubber, vulcanized or thermoplastic Determination of abrasion resistance using a rotating cylindrical drum device I
20、SO 4671:1999, Rubber and plastics hoses and hose assemblies Methods of measurement of dimensions ISO 4672:1997, Rubber and plastics hoses Sub-ambient temperature flexibility tests ISO 7233, Rubber and plastics hoses and hose assemblies Determination of suction resistance ISO 7326:1991, Rubber and pl
21、astics hoses Assessment of ozone resistance under static conditions ISO 8031, Rubber and plastics hoses and hose assemblies Determination of electrical resistance ISO 8033, Rubber and plastics hose Determination of adhesion between components ISO 8330, Rubber and plastics hoses and hose assemblies V
22、ocabulary ISO 2928:2003(E) 2 ISO 2003 All rights reserved3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 8330 apply. 4 Classification Hoses shall be one of the following types: type D: delivery hose; type D-LT: delivery hose, low-temperature; type SD
23、: suction and delivery hose, helix-reinforced; type SD-LTR: suction and delivery hose, helix-reinforced, low-temperature (rough-bore). type SD-LTS: suction and delivery hose, helix-reinforced, low-temperature (smooth-bore); All these types can be: electrically bonded, in which case the hose is addit
24、ionally designated and marked with the symbol M; electrically conducting by virtue of a conducting rubber layer, in which case the hose is additionally designated and marked with the symbol ; electrically discontinuous, incorporating a metallic wire connection to one end-fitting of the hose assembly
25、 only. 5 Materials and construction The hose shall consist of the following: a lining of rubber resistant to n-pentane; a reinforcement of layers of woven, braided or spirally wound textile material or braided or spirally wound wire; an embedded helical reinforcement (types SD, SD-LTR and SD-LTS onl
26、y); two or more low-resistance electrical-bonding wires (for hoses designated M only); an outer cover of rubber, resistant to abrasion and outdoor exposure, the cover being pricked to allow gas permeation; an internal, non-embedded helical wire, suitable for use at 50 C (type SD-LTR only). Assemblie
27、s shall incorporate metallic fittings attached to the hose by the assembler. Chlorinated materials shall not be used in contact with any stainless-steel materials. ISO 2928:2003(E) ISO 2003 All rights reserved 36 Dimensions 6.1 Nominal bore, internal diameter, outside diameter, minimum bend radius F
28、or hoses without built-in couplings, and when measured in accordance with method A of ISO 4671:1999, the internal diameter and outside diameter and their tolerances shall conform to the values given in Table 1 or Table 2, depending on the type. For hoses with built-in couplings, the outside diameter
29、s of Table 1 and Table 2 shall not apply. When tested by the method described in ISO 1746, the value of the minimum bend radius shall conform to the values given in Table 1 or Table 2, depending on the type. Table 1 Dimensions of hoses of types D and D-LT Nominal bore Internal diameter Tolerance Out
30、side diameter Tolerance Design minimum bend radius amm mm mm mm mm 12 12,7 0,5 22,7 1,0 100 15 15 0,5 25 1,0 120 16 15,9 0,5 25,9 1,0 125 19 19 0,5 31 1,0 160 25 25 0,5 38 1,0 200 32 32 0,5 45 1,0 250 38 38 0,5 52 1,0 320 50 50 0,6 66 1,2 400 51 51 0,6 67 1,2 400 63 63 0,6 81 1,2 550 75 75 0,6 93 1,
31、2 650 76 76 0,6 94 1,2 650 80 80 0,6 98 1,2 725 100 100 1,6 120 1,6 800 150 150 2,0 174 2,0 1 200 200 200 2,0 224 2,0 1 600 250 254 2,0 2 000 300 305 2,0 2 500 NOTE Nominal bores 250 and 300 apply to hoses with built-in couplings only. aThe design minimum bend radius is measured to the surface of th
32、e hose on the inside of the bend. ISO 2928:2003(E) 4 ISO 2003 All rights reservedTable 2 Dimensions of hoses of types SD and SD-LT Nominal bore Internal diameter Tolerance Outside diameter Tolerance Design minimum bend radius amm mm mm mm mm 12 12,7 0,5 22,7 1,0 90 15 15 0,5 25 1,0 95 16 15,9 0,5 25
33、,9 1,0 95 19 19 0,5 31 1,0 100 25 25 0,5 38 1,0 150 32 32 0,5 45 1,0 200 38 38 0,5 52 1,0 280 50 50 0,6 66 1,2 350 51 51 0,6 67 1,2 350 63 63 0,6 81 1,2 480 75 75 0,6 93 1,2 550 76 76 0,6 94 1,2 550 80 80 0,6 98 1,2 680 100 100 1,6 120 1,6 720 150 150 2,0 174 2,0 1 000 200 200 2,0 224 2,0 1 400 250
34、254 2,0 1 750 300 305 2,0 2 100 NOTE Nominal bores 250 and 300 apply to hoses with built-in couplings only. aThe design minimum bend radius is measured to the surface of the hose on the inside of the bend. 6.2 Minimum thickness of lining and cover When measured in accordance with ISO 4671, the minim
35、um thickness of both the lining and the cover of all hoses shall be 1,6 mm. ISO 2928:2003(E) ISO 2003 All rights reserved 57 Physical properties 7.1 Compounds The physical properties of the compounds used for the lining and cover shall conform to the values given in Table 3, when determined by the m
36、ethods listed in Table 3. Tests shall be carried out on samples taken either from the hose or from separately vulcanized sheets, vulcanized to the same cured state as the production hoses. Table 3 Physical properties of compounds Property Unit Requirements Method of test Lining Cover Tensile strengt
37、h (min.) MPa 10 10 ISO 37 (dumb-bell test piece) Elongation at break (min.) % 250 250 ISO 37 (dumb-bell test piece) Abrasion resistance (max.) mm 3 170 ISO 4649:2002, method A Ageing ISO 188:1998 (14 days at +70 C, air-oven method) Hardness, change from original value (max.) IRHD +10 +10 ISO 48 Tens
38、ile strength, change from original value (max.) % 30 30 ISO 37 Elongation at break, change from original value (max.) % 35 35 ISO 37 Effect of liquids Increase in mass (max.) % +10 ISO 1817, after 7 days immersed in n-pentane at +23 C Variation in hardness (max.) IRHD +10/3 ISO 1817, after 7 days im
39、mersed in n-pentane at +23 C and drying for 70 h at +40 C Reduction in mass (max.) % 5 10 (-LT types) ISO 1817, after 7 days immersed in n-pentane at +23 C and drying for 70 h at +40 C ISO 2928:2003(E) 6 ISO 2003 All rights reserved7.2 Finished hose When tested by the methods listed in Table 4, the
40、physical properties of the finished hose shall conform to the values given in Table 4. Table 4 Physical properties of finished hoses and hose assemblies Property Unit Requirements Method of test Hoses Proof test pressure (min.) bar 37,5 (no leakage or other signs of weakness) ISO 1402 Change in leng
41、th (max.) at proof test pressure. % Types D and D-LT: +5 Types SD, SD-LTR and SD-LTS: +10 ISO 1402 Change in twist (max.) at proof test pressure /m 8 ISO 1402 Resistance to suction (types SD, SD-LTS and SD-LTR only) at 0,8 bar for 10 min. No structural damage, no collapse ISO 7233 Burst pressure (mi
42、n.) bar 100 ISO 1402 Adhesion between components (min.) kN/m 2,4 ISO 8033 Ozone resistance of cover at +40 C No cracking observed under 2 magnification after 72 h ISO 7326:1991, method 1 up to 25 nominal bore, method 3 above 25 nominal bore; relative humidity (55 10) %; ozone concentration (50 5) pp
43、hm; elongation 20 % (method 3 only) Low-temperature flexibility: at 30 C (types D and SD) at 50 C (types D-LT, SD-LTR and SD-LTS) No permanent deformation or visible structural damage, no increase in electrical resistance, no impairment of electrical continuity ISO 4672:1997, method B Electrical res
44、istance Electrical properties of hose shall be such that electrical requirements for hose assemblies are met ISO 8031 Flammability Ceases to burn immediately, or no glowing visible after 2 min Annex A Coefficient of deformation (max.) of external hose diameter at min. bend radius (at an internal pre
45、ssure of 0,7 bar for types D and D-LT) T /D W 0,9 ISO 1746 Hose assemblies Proof test pressure (min.) bar 37,5 (no leakage or other signs of weakness) ISO 1402 Change in length (max.) at proof test pressure % Types D and D-LT: +5 Types SD, SD-LTR and SD-LTS: +10 ISO 1402 Change in twist (max.) at pr
46、oof test pressure /m 8 ISO 1402 Resistance to suction at 0,8 bar for 10 min (types SD, SD-LTS and SD-LTR only) No structural damage, no collapse ISO 7233 Electrical resistance /finished assembly M-type: max. 10 2 ; -type: max. 10 6 ; discontinuous type: min. 2,5 10 4ISO 8031 ISO 2928:2003(E) ISO 200
47、3 All rights reserved 78 Electrical resistance The electrical resistance of hoses and hose assemblies shall be determined by any of the three methods a) to c) listed below. a) Textile-reinforced hoses with bonding wires Two low-resistance bonding wires shall be incorporated into the hose constructio
48、n. Each of these shall run in a spiral. When attaching fittings to such hoses, the bonding wires shall be folded into the hose bore, between the lining and the fitting tail and extending approximately 1/3 of the length of the fitting tail into the bore. When determined in accordance with ISO 8031, the resistance along the bonding wires, in the case of hoses, or the resistance between the fittings, in the case of hose assemblies, shall not exceed 1 10 2 per manufactured length. When electrical continuity is demonstrated in this way, the hose shall be ma
