ISO 2928:2003

INTERNATIONAL ISO
STANDARD 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 pétrole liquéfié (GPL) en
phase liquide ou gazeuse et le gaz naturel jusqu'à 25 bar (2,5 MPa) —
Spécifications




Reference number
ISO 2928:2003(E)
©
ISO 2003

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ISO 2928:2003(E)
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ii © ISO 2003 — All rights reserved

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ISO 2928:2003(E)
Contents 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 Frequency 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

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ISO 2928:2003(E)
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 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 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 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 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 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.

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INTERNATIONAL STANDARD ISO 2928:2003(E)

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
WARNING — Persons using this International Standard should be familiar with normal laboratory
practice. 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 Standard 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 °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 latest 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 hoses 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
ISO 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 plastics 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 — Vocabulary
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ISO 2928:2003(E)
3 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: 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 additionally 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 Ω;
 electrically discontinuous, incorporating a metallic wire connection to one end-fitting of the hose
assembly 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 only);
 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).
Assemblies shall incorporate metallic fittings attached to the hose by the assembler.
Chlorinated materials shall not be used in contact with any stainless-steel materials.
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ISO 2928:2003(E)
6 Dimensions
6.1 Nominal bore, internal diameter, outside diameter, minimum bend radius
For 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 diameters 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 Outside Design minimum bend
Internal diameter Tolerance Tolerance
a
bore diameter radius
mm 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 ± 1,2 650
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.
a
The design minimum bend radius is measured to the surface of the hose on the inside of the bend.

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ISO 2928:2003(E)
Table 2 — Dimensions of hoses of types SD and SD-LT
Nominal Outside Design minimum bend
Internal diameter Tolerance Tolerance
a
bore diameter radius
mm 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 25,9 ± 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
250 254 ± 2,0 — — 1 750
300 305 ± 2,0 — — 2 100
NOTE Nominal bores 250 and 300 apply to hoses with built-in couplings only.
a
The design minimum bend radius is measured to the surface of the hose on the i
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